In the north the King of Hungary was making desperate efforts to recover Bosnia, and in his operations he received help from Ragusa. A few months after the murder of Stephen Tomašević, Matthew Corvinus invaded Bosnia, and with the help of several of the magnates, including Kosača’s son, Vladislav Vukčić, reconquered Dolnji-Kralj and Usora, with about thirty towns and fortresses, including Jajce, Zvečaj, Banjaluka, Tešanji, and Srebrenik, only Upper Bosnia and Podrinje remaining under the Turks. The King rewarded Vladislav for his services by giving him the counties of Uskoplje and Rama. In the spring of 1464 Mohammed again invaded Bosnia with 30,000 men and besieged Jajce, but was forced to retire. The part of Bosnia now under Hungary was formed into two Banats—Jajce and Srebrenik—and the Governor, Nicholas of Ilok, Vojvod of Transsilvania, was entitled “King of Bosnia,” so as to uphold the Hungarian claims over the whole country. In the south another Hungarian expedition was made in 1465 from the Narenta. The Ragusan Senate ordered a bridge to be built across that river, at the Republic’s expense, near the castle of Počitelj, so as to facilitate the passage of the Hungarian army, and all the necessary materials and workmen were sent there for the purpose. Two Hungarian envoys came to Ragusa to arrange the plan of campaign. The Herzegovina was still ruled by Kosača, but Turkish raids from southern Bosnia were frequent, and it was important to keep the enemy from the Narenta’s mouth.[418] Počitelj, a quaint and picturesque hill town, came to be the centre of a series of operations against the Turks, which lasted until 1470. In 1466 we find the Ragusans giving “4 schopetos parvos, 4 tarassios de minoribus,” 200 lbs. of powder, 1000 beams, and 1000 “clavos” for the defence of Počitelj, and two carpenters, two _marangoni_, and some boats. Three bombards, building materials, ropes, bullets, provisions, and more firelocks and boats were added later, together with a staff of boat-builders and engineers.[419]