Egypt's newly elected president has read the oath of office in Tahrir Square and defied the country's military rulers by saying: "I fear no one but God."
Mohammed Morsi of the Muslim Brotherhood addressed tens of thousands of mostly Islamist supporters in a strongly worded speech.
He spoke on the eve of his official swearing-in ceremony that was scheduled in front of a high court.
But many protesters called on him to take the oath in the square to defy the ruling generals who took power after Hosni Mubarak's driven from office.
Mr Morsi vowed that the power of people is above all and that no one can take away the president's authorities.
He is the first Islamist and the first civilian to win the presidency, a job held for nearly three decades by Mubarak.
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.
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 Mubarak's last prime minister Ahmed Shafiq.
Egyptians will be watching Mr Morsi's statements to see whether he will accept the restrictions on his power or try to use his position as an elected president to force the military to lift them.
His influence is hampered by a court decision that dissolved the country's first freely elected parliament, which was dominated by Islamists. The ruling generals have promised to transfer power to an elected president by Sunday.