Vassal States were a number of tributary or vassal states, usually on the periphery of the Ottoman Empire under suzerainty of the Porte, over which direct control was not established, for various reasons.
Some of these states served as buffer states between the Ottomans and Christianity in Europe or Shi’ism in Asia. Their number varied over time but notable were the Khanate of Crimea, Wallachia, Moldavia, Transylvania. Other states such as Bulgaria, the Eastern Hungarian Kingdom, the Serbian Despotate and the Principality of Serbia, 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). Areas such as holy cities and Venetian tributary areas of Cyprus and Zante were not fully incorporated either. Finally, some small areas such as Montenegro/Zeta and Mount Lebanon did not merit the effort of conquest and were not fully subordinated to the Empire.
Some states within the eyalet system included sancakbeys who were local to their sanjak or who inherited their position (e.g., Samtskhe, some Kurdish sanjaks), areas that were permitted to elect their own leaders (e.g., areas of Albania, Epirus, and Morea (Mani Peninsula was nominally a part of Aegean Islands Province but Maniot beys were tributary vassals of the Porte.)), or de facto independent eyalets (e.g., the Barbaresque 'regencies' Algiers, Tunis, Tripolitania in the Maghreb, and later the Khedivate of Egypt).
Outside the eyalet system were states such as Moldavia, Wallachia and Transylvania which paid tribute to the Ottomans and over which the Porte had the right to nominate or depose the ruler, garrison rights, and foreign policy control. They were considered by the Ottomans as part of Dar al-'Ahd, thus they were allowed to preserve their self-rule, and were not under Islamic law, like the empire proper; Ottoman subjects, or Muslims for that matter, were not allowed to settle the land permanently or to build mosques.
Some states such as Ragusa paid tribute for the entirety of their territory and recognized Ottoman suzerainty.
Others such as the sharif of Mecca recognized Ottoman suzerainty but were subsidized by the Porte.
During the nineteenth century, as Ottoman territory receded, several breakaway states from the Ottoman Empire had the status of vassal states (e.g. they paid tribute to the Ottoman Empire), before gaining complete independence. They were however de facto independent, including having their own foreign policy and their own independent military. This was the case with the principalities of Serbia, Romania and Bulgaria.
Some states paid tribute for possessions that were legally bound to the Ottoman Empire but not possessed by the Ottomans such as the Habsburgs for parts of Royal Hungary or Venice for Zante.
There were also secondary vassals such as the Nogai Horde and the Circassians who were (at least nominally) vassals of the khans of Crimea, or some Berbers and Arabs who paid tribute to the North African beylerbeyis, who were in turn Ottoman vassals themselves.
Other tribute from foreign powers included a kind of "protection money" sometimes called a horde tax (similar to the Danegeld) paid by Russia or the Polish-Lithuanian Commonwealth. It was usually paid to the Ottoman vassal khans of Crimea rather than to the Ottoman sultan directly.
Lordship of Prilep (1371-1395)
Dejanović noble family (1371-1395)
Principality of Wallachia (Eflâk Prensliği), 1396–1397, 1417–1861 with some interruptions.
Byzantine Empire c.1370-1402, c.1421-1453
Despot of Morea
Trebizond Empire 1456-1461
Principality of Moldavia (Boğdan Prensliği), 1456–1457, 1503–1861 with some interruptions; briefly annexed as an eyalet from 1595–96)
Sharifate of Mecca, 1517-1803
Archduchy of Austria, 1533-1606
Crimean Khanate (Kırım Hanlığı), 1478–1774
Budzhak Horde (? -1807)
Edisanskaya Horde (? -1770)
Edichkulskaya Horde (? -1770)
Dzhambuylutskaya Horde (? -1770)
Circassian principalities and tribes
Kabarda (? -1739)
Grand Duchy of Moscow (1521)
Muscovy (1571-1700 year tributary)
Yedisan (1684-1760s)
Kazan Khanate (Kazan Hanlığı), 1523: Kazan briefly conquered by Crimean Khanate, Sahib I Giray enthroned as Khan
Eastern Hungarian Kingdom
Hilaalee dynasty of The Maldives, 1565?-1597?
Principality of Transylvania (Erdel), 1570–1692 with some interruptions
Sultanate of Aceh, 1569-late 18th century
Sultanate of Malacca, (1459-1477) during the reign of Sultan Mansur Shah.
Kingdom of Bohemia, briefly in 1620 under Frederick I of Bohemia
Principality of Upper Hungary (modern-day Slovakia), 1682–1685 under Imre Thököly
Principality of Serbia (Sırbistan Prensliği), 1817–1830; further autonomy 1833–1878
United Principalities of Romania (Romanya Prensliği), 1862–1877
Khedivate of Egypt (Mısır), 1867–1914: de jure under Ottoman suzerainty, in effect fully autonomous, and from 1882 under British occupation; broke away from Ottoman suzerainty upon Ottoman entry into World War I on the side of the Central Powers and reformed as the "Sultanate of Egypt" which was declared a British protectorate on 5 November 1914, the day when Britain and France declared war against the Ottoman Empire. Britain also formally annexed Cyprus (under British administration since the Cyprus Convention in 1878, but nominally still an Ottoman territory) until 5 November 1914.
Principality of Bulgaria (Bulgaristan Prensliği), 1878–1908
Republic of Ragusa
Duchy of Naxos, 1566-1579
Principality of Samos (Sisam), 1835–1912: established as an autonomous tributary principality under a Christian Prince; annexed to Greece during the First Balkan War
Eastern Rumelia (Doğu Rumeli), 1878–1885: established by the Treaty of Berlin on 13 July 1878 as an autonomous province; in a personal union with the tributary Principality of Bulgaria on 6 September 1885 but remained de jure under Ottoman suzerainty; annexed by Bulgaria on 5 October 1908.
Cyprus (Kıbrıs), 1878–1914: established as a British protectorate under Ottoman suzerainty with the Cyprus Convention of 4 June 1878; annexed by Britain on 5 November 1914, upon Ottoman entry into World War I.
Qatar (Katar), 1872–1913
Cretan State (Girit), 1898–1912/13: established as an internationally supervised tributary state headed by a Christian governor; in 1908 the Cretan parliament unilaterally declared union with Greece; the island was occupied by Greece in 1912, and de jure annexed in 1913
Cossack Hetmanate: Protectorate and Sanjak of the Ottoman Empire (1655 - 1663) and (June 1669 - 1685)
Septinsular Republic
Lebanon running dynasties Ma'an (1516-1697) and Chehab (1697-1840)
The Principality of Transylvania (1543-1692 with breaks)
Abdalvadidov Kingdom (1554-1556)
Imereti kingdom (1555-1804)
Principality of Abkhazia (1555-1810)
Principality of Mingrelia (1557-1803)
