Dušan built a Balkan empire by sieges alone, and it lasted barely 25 years
In the 1340s Stefan Dušan doubled the size of Serbia without fighting a single field battle, taking city after city by siege. By 1346 he ruled from the Danube to the Gulf of Corinth and was crowned emperor. His son could not hold any of it, and the empire dissolved by 1371.
Dušan came to power by force. His father, King Stefan Dečanski, favoured a younger son, but most of the nobility and Archbishop Danilo backed Dušan, who had shown his skill at the battle of Velbužd. After the king raided Zeta, the province Dušan governed as heir, the son marched to Nerodimlje, besieged his father and made him give up the throne. The old king died imprisoned in the fortress of Zvečan.
Byzantium was the main target. In 1333, aided by the defector general Syrgian, Dušan took Ohrid, Prilep and Kastoria, though Syrgian's assassination stalled a move on Thessalonica. By 1345 his realm covered half the Balkans, larger than either Byzantium or the Second Bulgarian Empire. That year at Serres he declared himself tsar, and on 16 April 1346 in Skopje he was crowned Emperor of the Serbs and Greeks, a claim to the Byzantine inheritance. He also raised the Serbian church to a patriarchate and married Helena, sister of the Bulgarian tsar Ivan Alexander.
His legal work outlived his conquests. Dušan's Code, issued in 1349 and 1354, drew on Roman-Byzantine law and on Saint Sava's Nomocanon of 1219, governing both state and Orthodox Church. In December 1355, while preparing fresh campaigns, he died suddenly of an unknown illness.
Stefan Uroš V earned the nickname the Weak as provinces broke away and nobles ignored him. Ottoman forces were then spreading into Europe, and at the Battle of Maritsa in 1371 they crushed a Serbian army under Vukašin. Uroš died childless that December, and Serbia splintered among regional lords.
Source: Serbian Empire
