Tens of thousands of people in Cairo’s Tahrir Square erupted in feverish celebration as a leader of Egypt’s long-outlawed Muslim Brotherhood defied pundits, opinion polls and the full brunt of the former regime’s networks to become the nation’s first democratically elected president.

A week after Egypt’s first democratic presidential election and amid heightened anxiety over the conduct of the poll, Mohamed Morsi was on Sunday declared the country’s first civilian leader after decades of rule by military men. Mr Morsi, 60, defeated Ahmed Shafiq, the ex-air force commander and official in Hosni Mubarak’s regime, with 52 per cent of the vote, poll officials said.

The elevation of an Islamist to the highest post in the Arab world’s most populous and historically influential nation marks a milestone in the region where demands for political change were ignited 18 months ago by the self-immolation of a fruit vendor in Tunisia.