Siege of Bursa
The Siege of Bursa took place from 1317 until the capture of Bursa on 6 April 1326, when the Ottoman Turks deployed a bold plan to seize the city, which was back then known as Prusa. The Ottomans had not captured a city before; the lack of expertise and adequate siege equipment at this stage of the war meant that the city fell only after six or nine years.
The historian, Laonikos Chalkokondyles, notes that the Ottomans took advantage of the Byzantine [civil war of 1321–1328] to capture the city: "Andronikos decided that he should hold the throne himself, as his grandfather had already grown old, and so they fell out with each other. He was too stubborn to submit and caused endless trouble. He brought in the Kingdom of [Serbia (1217–1346)|Serbs] and allied himself with the leading Greeks in his struggle for the throne. As a result they could do nothing to prevent the Turks from crossing over into Europe. It was at this time that Prusa was besieged, starved out, and taken by Osman, and other cities in Asia Minor were also captured."
According to some sources Osman I died of natural causes just before the fall of the city, while others suggest that he lived long enough to hear about the victory on his death-bed and was buried in Bursa afterwards.