When President Zeroual - a former general - was elected in 1995, he was seen as the army's candidate.

So when he announced last September that he was standing down without completing his five-year term, there was speculation that he had fallen out with some of the generals.

In the race to succeed him, the key factor will be whether or not the army stands aside and allows a free contest, as Mr Zeroual has urged it to do.

The military's man

Seven candidates are competing.

The front-runner is Abdelaziz Bouteflika. A former foreign minister who has been out of political life for the last 20 years, he is seen as the choice of the military establishment.

Abdelaziz Bouteflika: The frontrunner

He also has the backing of the two main parties in the current ruling coalition - and of the powerful trade union federation, the UGTA.

Mr Bouteflika's main challenger is Mouloud Hamrouche, a former prime minister who is relying on his reputation as a champion of political and economic reform.

The Islamist's choice

Ahmed Taleb Ibrahimi, another former foreign minister, is the third of the front-runners. The country's main Islamist party - the FIS, or Islamic Salvation Front - has urged its supporters to vote for Mr Ibrahimi.

Ahmed Taleb Ibrahmi: Backed by Islamists

So the election may provide some clues as to the strength of Islamist opinion.

The FIS was on the verge of winning the country's first freely-contested general election in 1992.

But the army intervened, cancelled the election and outlawed the FIS, precipitating the political violence which has plagued the country ever since - at a cost of 70-80,000 lives.

A fourth candidate, Hocine Ait Ahmed, had been considered a strong contender.

But after twelve days of campaigning, the 73-year-old Ait Ahmed entered hospital after suffering a mild heart attack.

End of an era

The election marks the end of the Zeroual era, and hence of a distinct chapter in the Algerian drama.

When he became president Mr Zeroual committed himself to dialogue with the Islamists, in an effort to end the political violence. But the attempt failed - just why is still hotly debated -- and Algerians are left wondering whether his successor can do any better.