Question: When did Şehzade Mehmed Abid's father begin his rule of the Ottoman Empire?
Context: Şehzade Mehmed Abid (17 September 1905 – 8 December 1973) was an Ottoman prince, the son of Sultan Abdul Hamid II and his wife Naciye Hanım. Hümaşah Sultan (Ottoman Turkish: هماشاہ سلطان) was an Ottoman princess, daughter of Şehzade Mehmed of the Ottoman Empire.  She was a granddaughter of Sultan Suleiman the Magnificent (reign 1520–1566) and his legal wife, Hürrem Sultan. Mehmed VI (Ottoman Turkish: محمد السادس‎ "Meḥmed-i sâdis", وحيد الدين "Vahideddin", Turkish: "Vahideddin" or "VI.  Mehmed" ), who is also known as "Şahbaba" (meaning "Emperor-father") among his relatives, (14 January 1861 – 16 May 1926) was the 36th and last Sultan of the Ottoman Empire, reigning from 1918 to 1922.  The brother of Mehmed V, he acceded to the throne as the eldest male member of the House of Osman after the 1916 suicide of Abdülaziz's son Şehzade Yusuf Izzeddin, the heir to the throne.  He was girded with the Sword of Osman on 4 July 1918, as the thirty-sixth "padishah".  His father was Sultan Abdülmecid I and mother was Gülüstü Hanım (1830 – 1865), an ethnic Abkhazian, daughter of Prince Tahir Bey Çaçba and his wife Afişe Lakerba, originally named Fatma Çaçba.  Mehmed was removed from the throne when the Ottoman sultanate was abolished in 1922. The Şehzade Mosque (Turkish: "Şehzade Camii" , from the original Persian شاهزاده "Šāhzādeh", meaning "prince") is a 16th-century Ottoman imperial mosque located in the district of Fatih, on the third hill of Istanbul, Turkey.  It was commissioned by Suleiman the Magnificent as a memorial to his son Şehzade Mehmed who died in 1543.  It is sometimes referred to as the "Prince's Mosque" in English.  In a June 2016 attack, the windows of the mosque were shattered. Kamures Kadın (5 March 1855 – 30 April 1921, other names "Gamres, Kamres, Kamus, Qamures") ("Kamres" meaning "bringer of pleasure") was the first wife of 35th Ottoman Sultan Mehmed V, and the mother of Şehzade Mehmed Ziyaeddin of the Ottoman Empire. Hürrem Sultan (] , Ottoman Turkish: خرم سلطان‎ , "Ḫurrem Sulṭān"; 1502 – 15 April 1558) was the favourite and later the chief consort and legal wife of Ottoman Sultan Süleyman the Magnificent.  She had six children with Süleyman: Şehzade Mehmed, Mihrimah Sultan, Şehzade Abdullah, Sultan Selim II, Şehzade Bayezid, and Şehzade Cihangir.  She was one of the most powerful and influential women in Ottoman history and a prominent and controversial figure during the era known as the Sultanate of Women.  She was "Haseki Sultan" (favorite of the Sultan) when her husband, Süleyman I, reigned as the Ottoman sultan.  She achieved power and influenced the politics of the Ottoman Empire through her husband and played an active role in state affairs of the Empire. Şehzade Mehmed Abdülkerim (27 June 1906 – 3 August 1935) was an Ottoman prince, grandson of the 34th Ottoman sultan, Abdul Hamid II by his third son Şehzade Mehmed Selim.  In 1933, Abdul Kerim was invited to Japan by their government, presumably with an eye towards leveraging his status as the Ottoman pretender to aid the Japanese Empire in outreach to Central Asian Muslims in conflict with the Soviet Union. Abdul Hamid II (Ottoman Turkish: عبد الحميد ثانی‎ , "`Abdü’l-Ḥamīd-i sânî"; Turkish: "İkinci Abdülhamit" ; 21 September 184210 February 1918) was the 34th Sultan of the Ottoman Empire and the last Sultan to exert effective control over the fracturing state.  He oversaw a period of decline.  He ruled from 31 August 1876 until he was deposed shortly after the 1908 Young Turk Revolution, on 27 April 1909.  In accordance with an agreement made with the republican Young Ottomans, he promulgated the first Ottoman constitution of 1876 on 23 December 1876, which was a sign of progressive thinking that marked his early rule.  Later, however, he noticed Western influence on Ottoman affairs and citing disagreements with Parliament, suspended both the short-lived constitution and Parliament in 1878 and accomplished highly effective power and control. Şehzade Mehmed (1521–1543) was an Ottoman prince (şehzade), son of Sultan Suleiman the Magnificent and Hürrem Sultan.  He was assigned to rule in Manisa after his brother Şehzade Mustafa was sent to Amasya from there. Inşirah Hanım (Ottoman Turkish: انشراح خانم‎ ; 10 July 1887 – 10 June 1930) was the wife of Şehzade Mehmed Vahideddin, future Sultan Mehmed VI of the Ottoman Empire.
Answer: 31 August 1876