Key facts on Mubarak

* President Hosni Mubarak, 82, was thrust into office when Islamists gunned down his predecessor Anwar Sadat at a military parade in 1981. The burly former air force commander has proved a far more durable leader than anyone imagined at the time.

* He has resisted any significant political change even under pressure from the United States, which has poured billions of dollars of military and other aid into Egypt since it became the first Arab state to make peace with Israel, signing a treaty in 1979.