John I of Hungary was in continuous contact with the Sublime Porte starting in 1527, and his fights against the Habsburg side were supported by the Turks. This was inherited by his son John II Sigismundus and his followers who retreated to the Eastern parts of the Kingdom of Hungary after the conquest of Buda in 1541. This territory was called the Principality of Transylvania starting in 1570. It was an independent country that recognized Ottoman supremacy in international politics until 1691, then a directly governed province by Vienna until 1867, having developed significantly after that as part of the Kingdom of Hungary. After the defeat in World War I, it became part of Romania with a huge Hungarian minority. Transylvanians had an embassy building in the Balat district of Istanbul from the 1550s. After the territory of Transylvania passed to the Habsburgs, it was used by the kuruc (rebel Hungarians) of the exiled Imre Thököly, later on the members of the Rákóczi immigration. However, its owners were already residents of Istanbul in the second part of the 18th century. The original building stood until the end of the 19th century, which was mentioned in many memoires of Hungarian travellers. The area of the embassy is currently in ruins, with a coffeehouse next to it. The steep street leading there commemorates the Hungarian/Transylvanian connections as well: Macarlar Yokuşu/Hungarian Street.