The story of Muavenet-i Milliye commenced in 1908 at the Schichau-Werke shipyard in Elbing, Germany, where it was initially designated as S165, one of the S138-class torpedo boats. As she underwent final preparations, the Ottoman Navy acquired the ship and gave it the name Muavenet-i Milliye, which translates to "Support of the Nation". This renaming was emblematic of the funding provided through donations gathered by the Ottoman Navy Association.
Together with her three companion vessels -Yadigar-ı Millet, Numune-i Hamiyet, and Gayret-i Vataniye- Muavenet-i Milliye became part of the Ottoman fleet in March 1910. This addition coincided with the procurement of two pre-dreadnought battleships, Barbaros Hayreddin and Turgut Reis, marking a substantial enhancement in the Ottoman Navy's capabilities.
During the 1911 Italo-Turkish War, Muavenet-i Milliye was deployed to the primary destroyer flotilla, however, following some initial uncertainties at the onset of the conflict, the Ottoman fleet, including Muavenet-i Milliye, remained behind coastal defenses at the Dardanelles, having only limited encounters with the Italian navy.
When the Balkan War began, Muavenet-i Milliye, together with other ships of the Ottoman fleet moved to the Black Sea, undertaking a sequence of raids along the Bulgarian shoreline, which included daring assaults on Bulgarian artillery positions close to Varna. During December 1913, the vessel joined the I Division, engaging in diverse naval missions. A notable instance was the Battle of Elli on 16 December, during which Muavenet-i Milliye and her companion ships played a pivotal role in protecting the Ottoman battleship division. While this encounter did not yield major outcomes, it added to the ship's wartime record. Throughout the Balkan War, Muavenet-i Milliye maintained its patrols and engagements with Greek forces. On 22 February 1913, she joined a flotilla to support the cruiser Hamidiye’s operations in the Mediterranean, conducting reconnaissance around the Gulf of Saros and Imbros Island until mid-April.
When the First World War began, Muavenet-i Milliye was conducting training exercises in the Sea of Marmara. With the arrival of the German ships Goeben and Breslau into the Ottoman Navy, and Vice Admiral Souchon taking command, Muavenet-i Milliye participated in Black Sea operations on 29 October 1914, attacking Russian ports and ships in Odessa. After completing this mission, the ship returned to Istanbul and anchored at Haydarpaşa on 30 October 1914.
On 1 April 1915, Muavenet-i Milliye, along with cruisers Mecidiye and Hamidiye and destroyers Yadigar-i Millet, Taşoz, and Samsun, set out from Istanbul for another raid on Odessa. This operation failed, and the fleet returned to Istanbul on 4 April 1915. From 7 April, Muavenet-i Milliye and Gayret-i Vataniye began patrolling the Sea of Marmara against submarines. On 27 April, Muavenet-i Milliye escorted ships carrying troops and supplies to Çanakkale, protecting them from submarine threats. At one point, she came under attack by the Australian submarine AE-2 but suffered no damage.
As Muavenet-i Milliye was escorting ships and conducting anti-submarine patrols in the Sea of Marmara, the Allied forces, unable to penetrate the Dardanelles by sea, prepared for a land assault. They sent the cruisers Goliath, Euryalus, and Bacchant to strengthen their fleet. On 25 April 1915, supported by naval fire, the Allies landed at five points on the Gallipoli Peninsula but failed to make significant progress. The French troops requested naval assistance, leading to the dispatch of the British battleships Goliath and Cornwallis.
The heavy bombardment from these ships caused significant issues for the Turkish soldiers. The Fifth Army Command requested measures to counter this threat. Initially, three torpedo boats were considered for the mission, but they were deemed inadequate, and it was decided to use Muavenet-i Milliye instead. Muavenet-i Milliye departed on 10 May 1915, arriving in Çanakkale the same day. Captain Ahmet Saffet Bey and German liaison officer Lieutenant Rudolph Firle conducted reconnaissance until the operation date of 13 May 1915.
After completing preparations, Muavenet-i Milliye set off from Çanakkale at 7:00 pm on 12 May 1915, heading towards Soğanlıdere. The ship anchored at 8:25 pm and waited for the planned attack time during the night shift change of the enemy ships. At 12:45 am, Muavenet-i Milliye moved towards Morto Bay, evading detection by staying close to the shore. She eluded the British destroyers Beagle and Bulldog, and at around 1:00 am she closed on the battleships Canopus and Goliath, which were at anchor in Morto Bay. When asked for a password by Goliath's sentry, Muavenet-i Milliye responded with an international signal meaning "Ready”. As the sentry continued asking for a password, Muavenet-i Milliye advanced closer and launched three torpedoes at 1:15 am, hitting Goliath's bridge, funnel, and stern, causing a massive explosion. The ship capsized almost immediately taking 570 of the 700-strong crew to the bottom.
Muavenet-i Milliye was pursued by Allied destroyers but managed to evade them with the help of Turkish shore batteries. The ship returned to Soğanlıdere on 13 May 1915, and reported the successful mission. After spending the night at Paşa Limanı, the ship returned to Istanbul on 15 May 1915, anchoring at İstinye Harbor. The crew was celebrated and rewarded by the public and state officials upon their return.
After arriving in Istanbul, Muavenet-i Milliye continued its training for a while. She was then assigned to the Black Sea to escort and patrol Turkish ships transporting coal, ensuring their safety. Muavenet-i Milliye performed this duty until 19 January 1918, when it provided submarine security for the Yavuz during the Battle of Imbros. In June 1918, the ship participated in an operation to detain Russian ships in the Black Sea. Following this mission, Muavenet-i Milliye carried out patrol duties in the Dardanelles until the end of the war. After the Armistice of Mudros on 30 October 1918, all Ottoman naval ships, including Muavenet-i Milliye, were disarmed and withdrawn to the Golden Horn on 8 November 1918.
When the Republic of Turkey was proclaimed in 1923, Muavenet-i Milliye was not included in the new naval program. She was decommissioned and used as a storage ship at the Taşkızak Shipyard until 1953, when it was scrapped and dismantled at the same shipyard.
