sentences:  Their number varied over time but notable were the Khanate of Crimea, Wallachia, Moldavia, Transylvania and the Principality of Serbia from 1815 until its full independence half a century later.Other states such as Bulgaria, the Eastern Hungarian Kingdom, the Serbian Despotate and the Kingdom of Bosnia were vassals before being absorbed entirely or partially into the Empire.Still others had commercial value such as Imeretia, Mingrelia, Chios, the Duchy of Naxos, and the Republic of Ragusa (Dubrovnik).