Osman Pazvantoğlu (1758 – January 27, 1807, ) was an soldier, a governor of the Vidin district after 1794, and a rebel against Ottoman rule. He is also remembered as the friend of , a revolutionary poet, whom he tried to rescue from the Ottoman authorities in .
His grandfather was originally from the , and part of the guards of the city of , hence Osman's name: pasban-oğlu, "son of the guard". Initially a mercenary in service to the , Osman Pazvantoğlu disobeyed the latter on one occasion, and was saved from reprisals through Feraios' intervention.
Having gathered a large army of mercenaries, he rebelled against the , and, acting as an independent ruler, he minted his own coins and had diplomatic relations with foreign states (including the ). In 1798, he held territories which spread from the Danube to the and from Belgrade to . In 1793, he undertook a military expedition to the but was soundly defeated by the Serbs in Ottoman service at the .
The 1798 military expedition of Hüseyin Küçük (having 100,000 soldiers) failed in its goal to conquer Vidin and capture Pazvantoğlu, and indirectly resulted in the fall and execution of Prince , after Küçük accused him of not having provided the with enough funds. He also attempted to annex the but was stopped by 16,000 Serbian soldiers in service. In 1799, the Ottoman sultan forgave Pazvantoğlu's rebellion and agreed to make him a .
Pazvantoğlu often made violent raids in , where he often set on fire the cities which he plundered. In 1800, his troops, colloquially known as pasvangii, set on fire a large portion of the city of : out of 7,000 houses, only around 300 were still standing after the fire stopped. This caused Prince to hand in his resignation to Sultan Selim, a rare statement of defeat in the context of reigns.
In late January 1802, was gripped by panic after rumors spread that the pasha had sent his army in its direction. Prince left the city and ordered its defense by the remaining garrison of , but disagreements over payment owed led the troops themselves to discard the place; the city soon fell to widespread disorder and the brief rule of beggars and vagabonds (who apparently mimicked a ceremony) — this episode was ended by the violent intervention of Ottoman troops stationed in the vicinity, and ultimately led to Soutzos' deposition.
In 1809, retaliation campaign of led by culminated in the attack and partial destruction of (which was officially administered as an Ottoman , but had become a base for the rebellion leader).
Pazvantoğlu's incursions soon became infamous in all of Wallachia. The expression "as in the time of Pazvante", rather common in , was meant to indicate a time of trouble and ill-government; in time, it simply came to mean "extremely old".
In Vidin, , the capital of Pazvantoğlu's domain, there are several landmarks built during his rule that still stand today. These include a (built in 1801-1802) and a library (1802–1803) dedicated to the pasha's father. Both are classed as monuments of culture.
The complex is also thought to have also included a ( school) and a small Muslim cloister, both of which have not survived until today.
1.   ; Ionescu, p.242
2.   ; Roger Viers Paxton (1968). . Department of History, Stanford University. p. 13.
3.   ; Ionescu, p. 254, citing Zilot Românul
4.   ; Djuvara, p. 282
5.   ; Djuvara, p.283
·   ; , Între Orient și Occident. Țările române la începutul epocii moderne ("Between Orient and Occident. The Romanian Lands at the beginning of the modern era"), Humanitas, , 1995
·   ; Ștefan Ionescu, Bucureștii în vremea fanarioților ("Bucharest in the Time of the Phanariotes"), Editura Dacia, Cluj, 1974