"Sometimes, when leading families or merchants organized a government for their city, they not only provided for some power sharing through voting but took pains to reduce the probability that the government's chief executive could assume autocratic power. For a time in Genoa, for example, the chief administrator of the government had to be an outsider -- and thus someone with no membership in any of the powerful families in the city. Moreover, he was constrained to a fixed term of office, forced to leave the city after the end of his term, and forbidden from marrying into any of the local families. In Venice, after a doge who attempted to make himself autocrat was beheaded for his offense, subsequent doges were followed in official processions by a sword-bearing symbolic executioner as a reminder of the punishment intended for any leader who attempted to assume dictatorial power."
Power and Prosperity. Outgrowing Communist and Capitalist Dictatorships (New York: Basic Books, 2000), p. 39