President-elect Mohammed Mursi of Egypt has taken an informal oath of office before his supporters in Tahrir Square in Cairo.
Mr Mursi swore a symbolic oath and declared that there was no power above people power, telling the crowd that they were now the source of sovereignty and authority in Egypt.
The BBC Jon Leyne reports he will officially be sworn in on Saturday morning at the Supreme Constitutional Court.
Mr Mursi promised to be a "president for all Egyptians", adding:
"The revolution must continue until all its objectives are met."
He added: "I promise you that I will not give up on any of the powers given to the president" - a veiled reference to recent decrees by the ruling Supreme Council of the Armed Forces.
He also pledged to work for the release of civilians detained by the military and to seek justice for those killed and injured in last year's uprising.
He also said he would work to free Omar Abdel-Rahman, imprisoned in the United States over the bombing of the World Trade Center in New York in 1993.
At one point Mr Mursi opened his jacket to show the crowd he was not wearing a bulletproof vest, saying: "I am reassured, thanks be to God and to you. I fear nobody but God."
Mr Mursi also promised to take steps to develop Egypt's struggling economy and to conduct foreign affairs with "dignity".
Earlier, he performed Friday prayers at Cairo's al-Azhar mosque, one of the most prominent seats of learning in Sunni Islam.
The BBC reports he has sought to allay fears among some secular and Coptic Christian Egyptians that he will use his presidency to impose Islamic law.
Mr Mursi's campaign has said he plans to appoint a woman and a Coptic Christian as his vice-presidents.