Egyptians are all set to elect a president for the first time in a democratic contest that pits religious conservative groups against those who served under deposed President Hosni Mubarak.
Wednesday's poll is a novelty for a nation where elections during the 30-year rule of a man some called "Pharaoh" were thinly attended rigmaroles in which the result was a foregone conclusion.
This time Egypt's 50 million eligible voters are expected to turn out in force to determine who will lead the country after the generals who have overseen a transition marred by violence, protests and political deadlock, formally hand over power by July 1.
Egyptians elect first new president in post-Mubarak era
"Of course I will vote. I want change. We can't stay in this messy situation for the rest of our lives," said Wael Azmy, an accountant, who has taken the day off work to give him time to join the queues he expects to form outside polling stations.
Voters have been blitzed by three weeks of official campaigning, which ended on Sunday. Egypt held its first US-style televised presidential debate. Newspapers have carried interviews and campaign adverts. Banners and posters festoon the streets.
With none of the 12 candidates expected to secure more than half the votes to win outright in the first round on Wednesday and Thursday, a runoff between the top two is likely in June.
It will be the first time that ordinary Egyptians, ruled down the centuries by pharaohs, sultans, kings and military officers, will have a genuine chance to choose their leader.
But whoever wins faces a huge task to deliver changes that Egyptians expect to relieve a grim economic outlook. The military that was a pillar of Mubarak's rule is likely to remain a powerful political force for years.
The army, whose senior ranks also have extensive commercial interests, insists it does not want to hang onto power.
"With these elections, we will have completed the last step in the transitional period," General Mohamed el-Assar told a news conference on the eve of voting.
There is little reliable survey data to give any indication of which candidate will emerge as head of state.
The West and Israel, worried about its 33-year-old peace treaty with Egypt, are watching to see if proponents of political Islam add to their gains after sweeping most seats in a parliamentary vote that ended in January.
Many Gulf states are equally concerned about who will lead the regional heavyweight after their long-time ally Mubarak was ousted. Their conservative monarchies have so far emerged from a wave of Arab uprisings relatively unscathed.
Seeking to allay such worries, the Muslim Brotherhood's candidate, Mohamed Mursi, pledged in a final rally on Sunday that "we will not export our revolution to anyone".
Mursi was pitched into the race at the last minute after the Brotherhood's first-choice candidate was ruled out. He may lack charisma, but he can rely on the Brotherhood's vote machine.
His rivals include Abdel Moneim Abol Fotouh, who has drawn support ranging from liberals to religious conservatives; former foreign minister and Arab League chief Amr Moussa, who has been a public figure for years with strong name recognition; and Ahmed Shafiq, Mubarak's last prime minister, who like his former boss, once commanded the air force.
Making a late surge is Hamdeen Sabahy, a leftist inspired by Gamal Abdel Nasser, whose "Free Officers" overthrew King Farouk in 1952 and set up the system that has put military men in the presidency for the past 60 years.