This same year there was another disagreement with King Stephen, as we find the Venetian Government authorising the Ragusans to purchase a further supply of arms;[173] in 1349 and 1350 Venetian embassies were sent to Servia to protest against his raids on Ragusan territory, a Venetian galley stationed in the harbour as a protection,[174] and two _mangani_ or catapults were forwarded to the citizens.[175] Some of the Venetian documents on the subject allude to Bosnian as well as Servian raids. Klaić says that the Banus Stephen Kotromanić actually did make raids before 1345, but in that year made peace and never molested the Ragusans again. His nephews, however, the Nikolići counts of Hlum and Popovo, had many quarrels with Ragusa and raided her territory, and it is to them that the documents allude.[176] War now broke out between Servia and Bosnia, because the Banus would not consent to his daughter’s marriage with the King’s son, Uroš. The King invaded Bosnia on two occasions with a large army, and besieged the Banus in the royal castle of Bobovac, but could not capture him. These quarrels between Bosnia and Servia, like those between Servia and Bulgaria, were paving the way for the Turkish conquest, and the obscure battles in the Bosna and Drina valleys formed the prelude to the fatal day of Kossovo and the bondage of the South-Slavonic race. The Banus Kotroman died in 1353, and was succeed by his nephew, Stephen Tvrtko, who was the first King of Bosnia. He too was friendly to the Ragusans, and granted them important privileges.