Ahmed II bin Ibrahim bin Ahmed bin Mehmed (Ottoman Turkish: احمد ثانى Aḥmed-i sānī) (25 February 1643 – 6 February 1695) was the Sultanof the Ottoman Empire from 1691 to 1695. Ahmed II was born at Topkapı Palace, Constantinople, the son of Sultan Ibrahim (1640–48) by Hatice Muazzez Valide Sultan, and succeeded his brother Suleiman II (1687–91) in 1691.

Reign
During his short reign, Sultan Ahmed II devoted most of his attention to the wars against the Habsburgs and related foreign policy, governmental and economic issues. Of these, the most important were the tax reforms and the introduction of the lifelong tax farm system (malikane) (see tax farming). Following the recovery of Belgrade under his predecessor,Suleiman II, the military frontier reached a rough stalemate on the Danube, with the Habsburgs no longer able to advance south of it, and the Ottomans attempting, ultimately unsuccessfully, to regain the initiative north of it.

Among the most important features of Ahmed’s reign was his reliance on Köprülüzade Fazıl Mustafa Pasha. Following his accession to the throne, Sultan Ahmed II confirmed Köprülüzade Fazıl Mustafa Pasha in his office as grand vizier. In office from 1689, Fazıl Mustafa Pasha was from the famous Köprülü family of grand viziers, and like most of his Köprülü predecessors in the same office, was an able administrator and military commander. Like his father Köprülü Mehmed Pasha (grand vizier 1656–61) before him, he ordered the removal and execution of dozens of corrupt state officials of the previous regime and replaced them with men loyal to himself. He overhauled the tax system by adjusting it to the capabilities of the taxpayers affected by the latest wars. He also reformed troop mobilization and increased the pool of conscripts available for the army by drafting tribesmen in the Balkans and Anatolia. In October 1690 he recaptured Belgrade (northern Serbia), a key fortress that commanded the confluence of the rivers Danube and Sava; in Ottoman hands since 1521, the fortress had been conquered by the Habsburgs in 1688.

Fazıl Mustafa Pasha’s victory at Belgrade was a major military achievement that gave the Ottomans hope that the military debacles of the 1680s—which had led to the loss of Hungary and Transylvania, an Ottoman vassal principality ruled by pro-Istanbul Hungarian princes— could be reversed. However, Ottoman success proved ephemeral. On August 19, 1691, Fazıl Mustafa Pasha suffered a devastating defeat at Slankamen (northwest of Belgrade) at the hands of Ludwig Wilhelm von Baden, the Habsburg commander in chief in Hungary, fittingly nicknamed “Türkenlouis” (Louis the Turk) for his splendid victories against the Ottomans. In the confrontation, recognized by contemporaries as “the bloodiest battle of the century,” the Ottomans suffered heavy losses: 20,000 men, including the grand vizier. With him, the sultan lost his most capable military commander and the last member of the Köprülü family, who for the previous half century had been instrumental in strengthening the Ottoman military.
Under Fazıl Mustafa Pasha’s successors, the Ottomans suffered further defeats. In June 1692 the Habsburgs conquered Várad (Oradea, Romania), the seat of an Ottoman governor (beylerbeyi) since 1660. In 1694 they attempted to recapture Várad, but to no avail. On January 12, 1695, they surrendered the fortress of Gyula, the center of an Ottoman sancak or subprovince since 1566. With the fall of Gyula, the only territory still in Ottoman hands in Hungary was to the east of the River Tisza and to the south of the river Maros, with its center at Temesvár. Three weeks later, on February 6, 1695, Ahmed II died in Edirne Palace.
Marriages and Issue
He married Rabia Sultan and had two sons and one daughter:
• Şehzade Ibrahim (6 October 1692 – 4 May 1714), twin with Selim, became Crown Prince on 22 August 1703.
• Şehzade Selim (6 October 1692 – 15 May 1693), twin with Ibrahim.
• Asiye Sultan (24 December 1693 – 9 December 1695).
He married Sayista Khanum and had three daughters:
• Khadija Sultan (1692 – 1694).
• Atike Sultan (born and died 21 October 1694).
• Sarai sultan.