Mohamed Morsi, an Islamist who pledged to be a "president for all Egyptians" at his inauguration, faces mass rallies demanding his departure on Sunday's first anniversary of his taking office.
Twelve months after he was feted by cheering crowds in Cairo's iconic Tahrir Square, Morsi's Egypt is deeply divided and rocked by deadly violence that has killed eight people this week alone.
The opposition Tamarod ("Rebellion") movement has urged Egyptians to take to the streets to demand that Morsi resign. It claims to have collected an unverified 22 million signatures calling for a snap presidential election.
The embattled president warned of chaos in a nationally televised speech on Wednesday, and Western leaders have monitored developments with growing alarm.
"Egypt faces many challenges. The polarisation has reached a stage that could threaten our democratic experience and paralyse the nation and cause chaos," Morsi said.
He has acknowledged making "many mistakes" and repeated calls for a national dialogue.
A retiring individual, bearded and bespectacled, Morsi's informal manner and casual language endeared him to some during his first months in office.
But today, Cairo's walls are covered with graffiti depicting him variously as a sheep, a pharaoh or even a vampire.
He is the subject of much criticism and ridicule and is a favourite target of hugely popular satirist Bassem Youssef on his weekly television show.
Morsi, 61, is a former senior leader of the powerful Muslim Brotherhood and was imprisoned under Hosni Mubarak, his predecessor who was ousted in the 2011 uprising.
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His opponents accuse him of hijacking the revolution and concentrating power in Islamist hands.
But his supporters insist the woes facing Egypt -- corrupt institutions, a faltering economy and religious tensions -- were inherited from the previous regime.
Morsi's critics see him as a cunning Brotherhood apparatchik who is seeking to extend sharia (Islamic law) and return to an authoritarian regime rather than put Egypt on the path to democracy and economic progress.
On his frequent visits abroad, Morsi seeks to integrate Egypt with leading emerging nations such as China and Brazil, while maintaining ties with the West and specifically the United States, reassuring them he will uphold a 1979 peace agreement with Israel.
Morsi became the Brotherhood's presidential candidate only after its first choice, Khairat El-Shater, was disqualified from standing, and despite having been written off by many as an uncharismatic substitute.
But the powerful Islamist movement mobilised its formidable resources and supporters behind Morsi to beat former air force chief Ahmed Shafiq, Mubarak's last premier.
Born in the Nile Delta province of Sharqiya, Morsi graduated with an engineering degree from Cairo University in 1975. He later received a PhD from the University of Southern California, where he was also an assistant professor in 1982.
He was an MP from 2000 to 2005. He was detained for seven months in 2006 for taking part in a demonstration in support of reformist judges.
In 2010, Morsi become a spokesman for the Muslim Brotherhood and a member of its politburo. He made several anti-semitic comments which recently resurfaced in the press.
He was jailed again on the morning of January 28, 2011, a day after the Brotherhood announced it would join the protests that eventually toppled Mubarak.
Morsi was later sprung from jail in massive prison breaks across the country.
The Brotherhood believes in establishing an Islamic state gradually through peaceful means, but Morsi's focus has been mostly on issues affecting the majority of Egyptians since the revolt, such as the deteriorating economy.
Morsi is married, with five children and three grandchildren.