Teodato Ipato was assassinated and his throne usurped, but the usurper, Galla Gaulo, suffered a like fate within a year. During the reign of his successor, Domenico Monegario, Venice changed from a fisherman's town to a port of trade and centre of merchants. Shipbuilding was also greatly advanced and the pathway to Venetian dominance of the Adriatic was laid. Also during Domenico Monegario's tenure, the first dual tribunal was instituted. Each year, two new tribunes were elected to oversee the doge and prevent abuse of power.