During the First World War, Mesopotamia's operational theatre encompassed the fertile lands nourished by the Euphrates and Tigris rivers, aligning with the borders of contemporary Iraq. The challenging landscape, characterized by swamps and deserts, rendered traversing the terrain a formidable task. The Ottoman Empire annexed the region in the early 16th century, yet struggled to establish an efficient administrative structure. The vast expanse between Istanbul and the southernmost Mesopotamian city, Basra, spanned 3,470 kilometers, constituting a four-month journey for caravans.

Before the war, Mesopotamia hosted two Turkish units: XII Corps (comprising the 35th and 36th Divisions) stationed at Mosul and XIII Corps (including the 37th and 38th Divisions) based in Baghdad.

In the meantime, the British orchestrated a strategy to deploy troops to the Shatt-al-Arab region, where the Tigris and Euphrates rivers conjoined, flowing into the Persian Gulf, safeguarding their vested oil interests. Tasked with this mission was the 6th Poona Division, a reinforced infantry unit drawn from the Indian Army. Upon receiving intelligence on these intentions, the Turks swiftly relocated segments of the 38th Division to the Shatt-al-Arab's mouth, placing them under the command of Lieutenant Colonel Süleyman Askeri Bey. Simultaneously, the remainder of the Turkish defensive force took position in Basra.

The British offensive began with a naval barrage targeting the ancient fort at Fav, strategically positioned at the confluence of Shatt-al-Arab and the Persian Gulf. This fort, guarded by 350 Turkish troops and four cannons, found itself defenseless against the Indian forces, who successfully landed and seized control on 6 November. By the middle of November, a significant portion of the Poona Division had securely established itself ashore.

In pursuit of their strategic objectives, the Indian division set their sights on the town of Basra. The formidable stronghold was defended by a force of 2,900 troops under the command of Suphi Pasha. On 22 November, Basra succumbed to the advancing British forces, resulting in a Turkish loss of 1,200 prisoners, including Suphi Pasha himself, and three cannons.

Emboldened by this unforeseen triumph, the British troops pressed on along the river, where the retreating Turkish forces had regrouped at Qurna. Engaging in regimental-scale battles around the town, the British emerged victorious on 9 December, with Qurna falling into their hands. Turkish losses mounted with an additional 1,200 prisoners and nine cannons, leaving the 38th Division in ruins.

Recognizing the gravity of underestimating the Mesopotamian theatre, Enver Pasha took corrective measures. The 35th Division, led by Mehmet Fazıl Pasha, was summoned back to Iraq, while efforts were made to reconstitute the beleaguered 38th Division. The shifting tides of war compelled a reassessment of strategies and an acknowledgment of the crucial role played by the Mesopotamian front.

On the second day of January in the year 1915, Süleyman Askeri Bey assumed the Iraq Area Command and the Governorship of Baghdad. Despite his modest rank, he garnered recognition within the Committee of Union and Progress, earning the admiration of Enver Pasha. Valiant and committed, his worldview, at times, displayed a certain narrowness and childlike simplicity. Turkish historians recount his words, asserting "Deploying troops to Iraq is nothing but murder. We can easily draw the enemy to the sea using the local clans and utilize our forces to assail India and Beludjistan." Upon taking command, Süleyman Askeri Bey promptly dispatched letters to Arab sheikhs, seeking to rally them against the perceived "infidels." 

First Battle of Kut

Enver Pasha's directive to Süleyman Askeri Bey left no room for hesitation—reclaim the Shatt-al-Arab region at all costs. Dividing his forces in two, Süleyman Askeri Bey led the Euphrates Wing, set to advance to Basra through Nasiria. Meanwhile, the Tigris Wing fell under the charge of Mehmet Fazıl Pasha, comprising the 35th Division and Arab cavalry units.

The British maintained a cavalry brigade at Basra, securing the town of Shaiba at the southern entry point to Basra itself. Süleyman Askeri's forces initially seized Nasiria before venturing into the desert towards Qurna.

On the morning of 12 April, Turks launched an assault on the British camp at Shaiba with a force of 3,800 troops. Despite persistent attacks over the next two days, no tangible outcomes emerged. Following a counterattack by British cavalry, the Turkish offensive was halted. Turkish casualties amounted to 1,000 men, with an additional 400 taken as prisoners.

In pursuit of withdrawing Turks, the British forces forced them to retreat an additional 120 kilometers up the river to Hamisia. Meanwhile, wounded Süleyman Askeri Bey, who had fought at Shaiba, endeavored to lead the operation from his camp bed. Despite a brief stint in a Baghdad hospital for treatment, his dedication to his men prevailed. Disheartened, especially by the performance of his Arab levies, he succumbed to despair and took his own life.

Meanwhile in Istanbul, the General Staff lacked a proper Mesopotamia map. Initial attempts to sketch one with the help of individuals familiar with Iraq before the war proved futile. Subsequently, two German maps at a scale of 1/1.500.000 were acquired. Nurettin Pasha, assigned to command the Sixth Army (Iraq Area Command), received Enver Pasha's directives: staunchly defend every inch of Iraq and launch an attack when the situation stabilizes. Reinforcements were steadily streaming in.

With unexpected success in Mesopotamia, the British, including the Indian Office and the Indian General Staff, opted to continue their advance up the river. General Townshend assumed command upon reaching Qurna. Progressing, the British reached the river port of Amara on May 3. After a brief hiatus due to seasonal flooding, they seized Nasiria on the Euphrates on 24 July, capturing 1,800 Turkish soldiers.

The swift progression of the British upstream also influenced the Arabs, prompting a realization of British dominance. Consequently, they shifted allegiances, aligning themselves with British forces against the Turkish Army. In Amara, Arab forces pillaged military hospitals, resulting in the massacre of Turkish soldiers.

Recognizing the feebleness of the opposition, General Townshend seized the opportune moment. With the Mesopotamian summer concluding and the river at a low ebb, the conditions were propitious for a British advance. On 1 September, the manoeuvre commenced, culminating in the occupation of the river town of Kut-al-Amara by 26 September. The defence of Kut-al-Amara involved twelve Turkish battalions, including a significant contingent of Arab soldiers, supported by a battery of thirty-eight guns. At the break of dawn on 28 September, Townshend launched an assault on the Turkish positions, resulting in a decisive retreat by day's end. Kut-al-Amara fell into British hands, inflicting a toll of 1,700 casualties on the Turks and capturing 1,300 prisoners along with seventeen cannons.

Following the loss of Kut-al-Amara, Turkish forces tactically withdrew 150 kilometers upstream along the Tigris River, positioning themselves in Selman-ı Pak, the ancient Persian town of Ctesiphon, located 35 kilometers south of Baghdad.

Defending Selman-ı Pak

On the banks of the Tigris River, nestled in proximity to the revered city of Karbala, lay Selman-ı Pak—a fortified stronghold occupying a formidable front line spanning 10 kilometers along the left bank of the river. Nurettin Pasha, the strategic mind behind the defensive operations, meticulously shaped two lines of defense, maintaining a three-kilometer separation between them, while the protective embrace of the river secured his right flank.

As the 45th Division seamlessly integrated into Nurettin Pasha's forces in Selman-ı Pak, the 51st Division reinforced the ranks by 17 November. This augmentation brought with it seven infantry battalions and a battalion equipped with Schneider howitzers. Nurettin Pasha marshalled a force of 20,000 men, bolstered by 19 machine guns, 52 artillery pieces, and a contingent of cavalry. The initial defense line found its guardians in the 38th and 45th Divisions, while the 51st Division stood stalwart at the second line of defense.

In the early hours of 22 November, the British and Indian forces led by Townshend launched an assault on the Turkish lines at Selman-ı Pak. Artillery fire and naval bombardment from armed river boats provided crucial support to this offensive. Townshend's forces executed a strategic maneuver, dividing into four columns. Three columns engaged in a frontal assault, while the fourth, a blend of cavalry and infantry, maneuvered eastward to outflank the Turkish position, with sights set on Baghdad.

The column closest to the river encountered formidable resistance, halting their advance under the barrage of intense rifle and artillery fire before breaching the first Turkish line. Simultaneously, another column to the right achieved its initial objectives by capturing the first defensive line, albeit at the cost of substantial casualties.

On the noon of that fateful day, the British cavalry endeavored to outflank the Turks, their efforts, however, proving unsuccessful. Despite this setback, the British forces began to gain the upper hand, prompting Nurettin Pasha to issue orders for a counter-attack by the 51st Division, which had been held in reserve. The ensuing combat persisted until late evening, exacting a heavy toll on both sides.

The following day saw yet another endeavour by Townshend to flank the Turks through a cavalry assault, only to be thwarted by a formidable sandstorm. Undeterred, Nurettin Pasha sought to resist the British advance by deploying whatever troops were at his disposal. Regrettably, he could only reclaim a portion of the territory lost the preceding day. Townshend, confronted with a seemingly insurmountable challenge, had secured the first line but struggled to make further headway. The toll on his forces was severe, with panic-stricken Indian troops surrendering in desperation.

On 25 November, Townshend made the decision to order a withdrawal. The retreat, closely shadowed by Turkish forces and harassed by Arab assailants, led the exhausted and diminished British contingent back to the protective confines of Kut-al-Amara, ultimately reaching their destination on 3 December. In the aftermath of the clash at Selman-ı Pak, the British forces suffered a staggering 4,500 casualties, while Turkish losses amounted to 9,500 out of a total force of 35,000 men, with the 45th Division alone sustaining a 65 percent loss of its personnel.

Second Battle of Kut

In the interim, the Turkish Sixth Army underwent restructuring, forming two distinct corps known as the XIII and the XVIII. Nurettin Pasha assumed command under the 72-year-old German Field Marshal Colmar von der Goltz. Nurettin, discontent with this arrangement, conveyed his sentiments in a cable to the High Command in Istanbul: “The Iraq Army has already demonstrated its independence from Goltz Pasha's military expertise... The decision to dispatch a non-Muslim general to Iraq, a region with a predominantly Muslim populace, and where we have declared a Holy War, is noteworthy.”

The Sixth Army diligently pursued the withdrawing British forces into Kut. Commencing on 7 December 1915, the siege of Kut unfolded, with Turkish divisions encircling the town. A network of trenches was meticulously crafted across the neck of the Tigris bend, effectively isolating Kut from Basra. Meanwhile, Townshend, the British commander, estimated the availability of supplies in Kut for approximately a month. Despite his proposal for a strategic withdrawal, General John Nixon, commander of British forces in Mesopotamia, dismissed the idea. Instead, he instructed Townshend to persist and engage as many Turkish troops around Kut as feasible. A relief force, commanded by General Aylmer, was mobilised with the intent to reach Kut.

In December 1915, Turkish forces mounted multiple offensives, each met with steadfast resistance. Simultaneously, additional troops arrived in Mesopotamia from the Third Army. The onset of 1916 witnessed the Turkish XVIII Corps, comprising the 45th and 51st Divisions, encircling the town, while the XIII Corps, with the 35th and 52nd Divisions, obstructed the British relief force approximately 30 km downstream along the Tigris.

On January 20, Enver Pasha replaced Nurettin Pasha with his own uncle, Colonel Halil Bey. Although Field-Marshal von der Goltz nominally oversaw the entire Mesopotamian campaign, daily operations were delegated to Turkish commanders.

Throughout January 1916, Townshend and Aylmer initiated multiple offensives in a bid to breach the Turkish lines, all met with resolute repulsion. Halil Bey, cognizant of the adverse conditions faced by the British, refrained from squandering his forces when holding the upper hand. The British, confronted with the dire choice of starvation or surrender, found their attempts thwarted.

In February, Halil Bey welcomed the 2nd Infantry Division as reinforcements, bolstering the XIII Corps in their defensive stance. The strategic deployment of this unit marked a pivotal juncture in the Mesopotamian theatre.

In March and April of 1916, a series of valiant British endeavours unfolded in an attempt to rupture the encirclement and General Aylmer tirelessly sought to relieve Kut. These efforts proved futile, and the toll they exacted was grievous. Both adversaries endured substantial casualties, leaving Townshend in Kut-al-Amara teetering on the brink of despair as provisions dwindled. Disease proliferated unchecked, defying remedy.

On 24 April, the paddle steamer Julnar embarked on a perilous mission to reach the beleaguered town by river, laden with 270 tons of essential supplies. Departing from the port of Felahiye at approximately 7:00 pm, Julnar sailed under the cloak of darkness, its lights extinguished to evade detection amidst the tumult of British artillery targeting Turkish coast batteries. With cunning finesse, the vessel navigated the initial defense lines unscathed, advancing resolutely towards Kut.

However, as Julnar reached the Maxis Pass, the Turkish 3rd and 7th Regiments unleashed a barrage of fire, causing catastrophic explosions on board. Lives were lost, including that of the captain, and after enduring an hour and a half of relentless onslaught, Julnar found itself grounded, its survivors taken captive. The ship, laden with flour, rice, biscuits, and canned meat, became a coveted prize for the Turkish troops grappling with their own food shortages.

Despite sporadic attempts to airdrop meager supplies to Kut, the provisions fell woefully short of the desperate needs of the beleaguered British forces. The struggle for sustenance and survival in the unforgiving theatre of war persisted.

Field Marshal von der Goltz succumbed to cholera on 19 April. Shortly thereafter, Townshend, facing the inevitable, chose to capitulate. On 26 April, he sought a six-day armistice and authorization for a ten-day supply of provisions to be delivered to the besieged town. The following day, Halil Bey initiated discussions with Townshend. Throughout the negotiations, the Turkish representatives insisted on an unconditional surrender. In response, Townshend proposed a settlement comprising one million pounds sterling, surrendering all firearms within the town, and pledging that his men would refrain from further hostilities against the Turkish army.

Simultaneously, the British garrison in Kut utilized the armistice period to eliminate any remaining valuable assets in the town, including howitzers, ammunition, and supplies. Ultimately, Townshend found himself compelled to surrender without conditions.

At 1:00 pm on 29 April 1916, concluding a siege lasting 147 days, a Turkish infantry regiment entered Kut-al-Amara to accept the surrender. By 2:30 pm that day, the Ottoman flag adorned the Town Hall. Townshend yielded a total of 13,309 men, encompassing 272 British and 204 Indian officers, along with 40 artillery pieces, three airplanes, two river steamers, and 40 automobiles. The toll of the siege on the British forces included 1,000 fatalities in combat, 7,000 wounded, and 731 succumbing to diseases and starvation.

Colonel Halil Bey, in his memoirs, enumerated Turkish losses: "My army suffered the loss of over 300 officers and 10,000 men throughout the siege of Kut and the encounters with relief forces. Conversely, we took five generals, 481 officers, and 13,300 men from the British army as prisoners of war. The casualties of the British relief force amounted to 30,000 men."

On 1 May, General Townshend and his entourage were dispatched to Baghdad. Following a brief sojourn in the city, on 12 May, Townshend, accompanied by fellow British officers, departed Baghdad under the watchful eye of Lieutenant Colonel İshak Bey. Venturing through Anatolia for a span of 20 days, Townshend eventually reached Istanbul. En route, a rendezvous occurred in Pozanti with Enver Pasha, who, at the time, assured Townshend of his fair treatment as a prisoner of war. Subsequently, General Townshend spent the duration of the war confined under house arrest on Büyükada, one of the Prince Islands nestled in the Sea of Marmara.

Halil Bey, who swiftly ascended to hero status overnight, attained the rank of Brigadier General and was bestowed the honorary title of "Pasha" at the youthful age of 33. Following the capture of Kut-al-Amara, the Mesopotamian campaign reached a stalemate. Halil Pasha commenced the fortification of the Euphrates and Tigris riverbanks, resulting in a period of relative inactivity throughout the remainder of 1916.

The prudent course of action for the Ottoman High Command post the triumph at Kut-al-Amara would have entailed reinforcing and consolidating their positions. Such a strategy would have fortuitously repelled any renewed British offensive, thereby maintaining control of Iraq. Regrettably, this astute approach was neglected. Instead, Enver Pasha opted to redirect the existing Mesopotamian troops for a campaign in Iran against the Russians. Halil Pasha vehemently opposed this plan, perceiving it as a reckless venture destined for calamity. His dissent manifested through numerous letters and cables addressed to Enver, expressing his disapproval. Nevertheless, given Enver's authoritative position, the XIII Corps was dispatched to Iran.

 

"At that time we had won a magnificent victory in Iraq. But what we won was just a battle. The war was still going on. Therefore we should have left the victory behind and plan what we should be doing next. It was obvious that the British would not let us get away with it. There would be surely a revenge, a bigger settlement…. However, it was not the logic, which was working, it was dreams. Some German officers in Baghdad were playing some weird games. It was all about Iran!… One day I received an order from the High Command in Istanbul. It was asking me to leave sufficient forces to defend Tigris and to use the rest of my forces to reinforce the Iranian front and capture the town of Kermanşah. Yes, it was only dreams!… This would be nothing but an adventure. I immediately replied to the High Command. I said that the British, who didn’t forget their defeat at Kut, have now gathered a force of 100,000 rifles only 110 kilometers south of Baghdad. When they are doing this, it would be only an ignorant and bloody adventure if we move our forces from the Tigris to some place in the middle of Iran. However, the Deputy Head Commander was insisting on operations in Iran. When they were insisting, I was refusing." (Halil Pasha in his memoirs)

In the latter half of 1916, unbeknownst to Enver, significant transformations were underway within the British military presence in Mesopotamia. Prior to the fall of Kut, reliance on the Indian General Staff for Mesopotamian operations had been the norm. However, a resolute decision emanated from London to assume direct control of the campaign. General Sir Frederick Stanley Maude was dispatched to take command of the theatre, and two newly formed infantry divisions were placed under his charge. By the year's end, his force comprised 166,000 individuals, with 107,000 hailing from India. Notably, Maude orchestrated the establishment of a formidable river fleet.

This strategic manoeuvre by Maude prompted Halil Pasha to consolidate his forces along the Tigris route. The XVIII Corps, led by Colonel Kazım Bey, witnessed reinforcement, now boasting three divisions: the 45th, 51st, and 52nd.

Baghdad Lost

Satisfied with the nearing completion of British preparations, Maude sought and, after a brief pause, secured permission from London for an advance upon Baghdad. The British offensive commenced on the night of 13/14 December on both banks of the Tigris. Hindered by heavy rain, the progress was deliberate, with a paramount focus on minimizing casualties. It required a full two months to eliminate resistance on the west bank below Kut, culminating in the capture of the fortified Hadairi Bend on 29 January 1917. By 17 February, British forces reached Sannaiyat, positioned 20 kilometers south of Kut.

On 23 February, Maude orchestrated a dual-flank attack, successfully crossing the Tigris river. Recognizing the looming threat of encirclement, Halil Pasha swiftly authorized a strategic withdrawal. Rear guard actions provided enough time for the Turks to evacuate the majority of their infantry.

The new Turkish defensive line traced the Diyala River, situated 15 kilometers below Baghdad. Halil Pasha found himself with a mere 12,500 men for the city's defence. The High Command, acknowledging the error of dispatching the XIII Corps to Persia post the Kut victory, under the leadership of Ali Ihsan Bey, ordered its return to Mesopotamia. Alas, the XIII Corps could only reach Hanekin, on the Iraq-Iran border, by 14 March, covering a distance of 400 kilometers in three weeks. By then, the city of Baghdad had already fallen.

On 5 March, General Maude recommenced his march along the eastern bank of the Tigris. Within three days, the British forces had reached the Diyala. Despite an initial unsuccessful attempt to traverse the vigorous and swift-flowing river, night-crossings managed to establish a modest bridgehead the following evening. General Maude's strategic objective was to encircle the Turkish forces and progress directly towards Baghdad.

As dawn broke on 10 March, Halil Pasha opted to withdraw from his position, redirecting efforts to safeguard the Baghdad-Berlin railway. Operations for the day were interrupted by sandstorms; when the weather subsided, Halil Pasha had resolved to initiate a comprehensive retreat from Baghdad itself. Consequently, at 8:00 pm on 10 March, the evacuation of Baghdad was set in motion.

The ensuing day witnessed General Maude's triumphant entry into Baghdad, greeted with jubilation by the local Arab populace. Baghdad, a city held by the Ottoman Empire for centuries, held immense emotional significance for the Turks. While the loss of Baghdad did not represent a significant strategic setback, it constituted a profound psychological blow.

Halil Pasha directed his forces approximately 60 kilometers up the Tigris. Subsequently, the right flank of the Sixth Army rested at Ramadiya on the Euphrates, and the left flank extended into Persia. Headquarters were relocated to Mosul. In contrast, General Maude, without pausing to revel in his victory in Baghdad, pressed onward in pursuit of capturing the railway at Samarrah. Subsequent large-scale operations were predominantly suspended until the arrival of autumn.

British supply lines were inadequate, the coming Mesopotamian summer was to be tough, prompting General Maude's concern about potential new armies under Halil Pasha. By late March 1917, a stabilization of the situation occurred, marking Baghdad's permanent departure from Turkish history.

In September 1917, General Maude resumed operations, focusing on Ramadiya. Encircling the Turkish garrison, the British captured numerous ridges above the town. A Turkish attempt to escape on 28 September 28 was thwarted by British cavalry, leading to the surrender of Turkish forces next day.

General Alexander Cobbe, leading two divisions, advanced up the River Tigris to confront newly established Turkish defensive positions north of Samarrah. On 5 November, Cobbe successfully attacked Turkish lines, albeit with heavy British cavalry losses during a charge on the Turkish second lines. The Turkish troops were compelled to withdraw.

Tragically, General Maude, the adept commander of British operations in Mesopotamia, succumbed to cholera on 18 November. His replacement was Gen. William Marshall.

Throughout 1918, the Mesopotamian theatre remained relatively tranquil. Troop movements to Palestine and Turkish reinforcements characterized the year, reflecting a collective reluctance to engage in hostilities.

As the war drew to a close, London turned its attention to post-war considerations. The strategic importance of seizing Mosul and its abundant oil resources became evident. Clearing the area of lingering Turkish influence was imperative before the impending armistice.

On 23 October 1918, General Cobbe led a British force from Baghdad, covering an impressive 120 kilometers within a mere two days. Their destination was the Little Zap River, where an encounter with the Turkish Sixth Army, commanded by Ismail Hakkı Bey, was anticipated.