Difficulties in the rule of the sea brought further changes. Until 1545 the oarsmen in the galleys were free sailors enrolled on a wage. They were originally Venetians, but later Dalmatians, Cretans and Greeks joined in large numbers. Because of the difficulty in hiring sufficient crews, Venice had recourse to conscription, chaining the oarsmen to the benches as other navies had already done. Cristoforo da Canal was the first Venetian to command such a galley. By 1563, the population of Venice had dropped to about 168,000 people.