Egypt's President Mohamed Morsi takes a symbolic oath in Tahrir Square
In a strongly worded speech, Mr. Morsi read the oath of office in Tahrir Square and defied the country's military rulers by saying "I fear no one but God".
Mr. Morsi, of the Muslim Brotherhood, is the first Islamist and the first civilian to win the presidency.
But he is already facing a serious challenge after the Mubarak-era military rulers who oversee the transition took a series of decisions undermining the powers of his office before his swearing-in, which was scheduled for Saturday.
His visit to Tahrir is also a nod to the protesters who supported his bid for leadership in a bitter campaign that pitted him against Hosni Mubarak's last Prime Minister Ahmed Shafiq.
Many protesters called on him to take the oath in the square to defy the ruling generals who took power after Hosni Mubarak's ouster.
Mr. Morsi vowed that the power of people is above all and that no one can take away the president's authorities.
The ruling generals have promised to transfer power to an elected president by Sunday but they also have given themselves sweeping powers that undercut the authority of the president.
The constitutional declaration – issued days before the winner of a run-off vote was announced – also designated the generals the country's legislature in place of the disbanded parliament.
Source: Telegraph