The Athenian navy was different from than army in that the expenses were usually privately born by a wealthy citizen who was called a trierarch. Leading citizens were expected to sponsor one or more ships and bear all the costs. The sailors were the poorer citizens who could not afford the armor required to be a hoplite. All they provided was a wooden oar. The paying of judges was quite an innovation as citizens were thought to have a responsibility to the city state. This did not occur until the mid 5th century.