The two top Islamists running in Egypt's first real presidential race share a common history.
Abdel Moneim Aboul Fotouh, a physician, is a former senior leader in the Muslim Brotherhood whose moderate stance has made him popular not only with Islamists, but with liberal and secular Egyptians.
Mohammed Morsi, an engineer, heads the Brotherhood's political party, which holds nearly half the seats in parliament.
Yet despite their common political background, the two men are bitter rivals.
The competition between them could also split the vote among Islamists, and both of them trail Amr Moussa, the former secretary general of the Arab League, in the run-up to voting that starts on May 23.