One difference between the appointment of a new Doge in Venice and a new Caliph in the Islamic world is:

the Doge is elected by representatives of the Grand Council, the Caliph by birthright or consensus.

the Doge is selected by district and votingmock, the Caliph by approval of provincial representatives.

the Doge $\text{'}$s election carries over two weeks, the Caliph's three months.

the Doge is chosen according to financial data and the Caliph is identified by omen