1387--Genoa concludes formal treaty with Murad. Murad, with army containing Greek, Serbian and Bulgarian contingents, defeats Alaeddin of Karamania at Konia, but has to withdraw without tangible results. 1388--Venice concludes commercial treaty with Murad. 1388--Osmanlis are defeated by Serbians and Bosnians at Plochnik, thus preventing invasion of Bosnia. League of Serbians, Bosnians, Bulgarians, Wallachians, and Albanians formed against the Osmanlis. First Ottoman army enters Greece upon invitation of Theodore Palaeologos to fight against the Franks. 1389--Osmanlis destroy Serbian independence at Kossova. Murad is assassinated on the battle-field. Bayezid succeeds to the throne, and has his brother Yakub strangled. BAYEZID (1389-1403). 1387--Bayezid marries sister of Stephen, son of Lazar, and makes Serbians his allies. 1390--First Ottoman naval expedition makes raid on Chios, Negropont, and Attika. First Ottoman raids into Hungary. 1391--Second invasion of Karamania, followed by siege of Konia, results in cession by Alaeddin of north-western portion of Karamania. First Ottoman siege of Constantinople. 1392--First defensive campaign against Sigismund is fought in Bulgaria. Hearing that Timurtash had been defeated by Karamanlis, Bayezid transports army to Asia, and destroys Alaeddin’s army at Ak Tchaï. The Osmanlis are now the dominant race in Asia Minor. 1394--Osmanlis first appear in the Adriatic at the mouth of the Boyana. 1395--Bayezid summons Ottoman vassals to his court at Serres. Ottoman siege of Constantinople becomes pressing. 1396--Crusade of Western chivalry, co-operating with Sigismund of Hungary, meets with disaster at Nicopolis in Bulgaria. Ottoman invaders of Wallachia are defeated at Rovine, but in raids into Hungary Peterwardein is burned, and sixteen thousand Styrians carried off into captivity. 1397--First Ottoman invasion of Greece. In the Peloponnesus, Argos is taken by assault. After defeat at Megalopolis, Theodore becomes Ottoman vassal. 1397-9--Movement of Moslem Anatolian population into the Balkan peninsula. 1398--Osmanlis and Serbians make destructive raid on Bosnia. 1400--Timur captures and destroys Sivas. 1402--Timur defeats and makes prisoner Bayezid at Angora, overruns Asia Minor, occupies Brusa, and takes Smyrna from the Christians by storm. 1403--Timur withdraws to Samarkand. Bayezid, still a prisoner, dies on the homeward march at Ak Sheïr. His sons dispute the succession. III. PROGRESS OF OTTOMAN CONQUEST UNDER THE FIRST FOUR SOVEREIGNS OSMAN (1299-1326) 1299--Osman, local chieftain at Sugut, has extended his conquests from the valley of the Kara Su westward to Yeni Sheïr. 1308--Kalolimni, island in the Sea of Marmora, becomes first Ottoman maritime possession. Ak Hissar, at the entrance to plain of Nicomedia, and Tricocca, which ensured land communication between Nicaea and Nicomedia, are captured.