In 1383 Tvrtko had become so powerful on the Dalmatian coast that the Senate recognized him as ‘king of Serbia, Bosnia and the Riviera’, and bestowed upon him the privilege of Venetian citizenship.[400] It was evidently the intention of Venice to favour Tvrtko as an opponent to Louis of Hungary, who had himself taken in 1382 the title of ‘king of Serbia, Dalmatia and Bulgaria’.[401] Venice lost her grip upon or interest in the east coast of the Adriatic for a few years immediately following the treaty of Turin. We have already seen how in 1384 the Senate professed a willingness to treat with the Osmanlis on the basis of giving up Scutari. In 1385 they became indifferent to currying further the favour of Tvrtko, and sent an embassy to press him for the payment of money due to Venice.[402] Tvrtko continued to consolidate his position on the Dalmatian coast, until the capture of Nish influenced him to aid Lazar against the Osmanlis. It was not a moment too soon. An Ottoman army had already crossed the Vardar and was marching forward for the invasion of Bosnia. Thirty thousand Serbians and Bosnians under the command of Tvrtko and Lazar met the invading army at Plochnik, in the valley of the Toplika. Of twenty thousand Osmanlis scarcely one-fifth escaped death or captivity.[403] The Bosnians successfully opposed two other Ottoman armies at Rudnik and Biletchia.[404] A delirium of joy spread through the Slavic population of the Balkans at the news of the battle of Plochnik. The uninterrupted chain of thirty years of Ottoman victories had been broken. The slavery and horror of military service with the Osmanlis, price of their vassalage, so vividly depicted by the survivors of the Karamanian campaign, had made the Slavs desperate. This victory, following closely upon the moral revolt against the Osmanlis, gave them hope. The South Slavs are like children in the extremes of their emotions. Tears to laughter--laughter to tears: easily despairing, as easily hopeful, and from as little cause. The slightest reverse brings distrust in their ability to cope with forces that have once successfully opposed them. Slight success brings overwhelming confidence, and leads to colossal mistakes of judgement. With this trait of character is coupled an intuitive distrust of one’s neighbour, of the disinterestedness of his motives, and an intuitive resentment of ‘the other fellow’ doing something better than you do it. This makes impossible solidarity and _esprit de corps_. The South Slavic character explains the series of events which brought the Serbians to their final and irretrievable disaster.