ISLAMABAD - Pakistan's former military ruler Pervez Musharraf on Tuesday faces trial for treason over his imposition of emergency rule in 2007, charges he has dismissed as politically motivated.
The 70-year-old is expected to appear in person before a specially-convened court in the capital Islamabad, after legal efforts to have the tribunal ruled invalid failed.
Security around the court was tight for the man who led Pakistan into its uneasy alliance with the US in the "war on terror" and now lives under heavy armed guard because of Taliban threats to his life.
Armed government paramilitary Rangers were stationed around the National Library building, where the hearing is to take place, and shipping containers put in place to form a security barrier to the compound.
It is the first time in Pakistan's history that a former military ruler has been put on trial for treason.
The case puts the government, which brought the charges, on a collision course with the all-powerful army, which faces the embarrassment of having its former chief tried by civilians.
Prime Minister Nawaz Sharif, who won a third term in May's general election, was the man Musharraf ousted in his 1999 coup and the former general's lawyers say he is using the case to exact revenge.
Since returning from self-imposed exile in March to run in the election, Musharraf has faced a range of serious criminal cases dating back to his 1999-2008 rule.
He stands accused of murder over the death of former prime minister Benazir Bhutto, killed in a gun and suicide attack in December 2007, as well as charges over the death of a rebel leader, a deadly military raid on a radical mosque and the detention of judges.
Musharraf was put under house arrest in April over the cases but was granted bail in each, one by one.
There have been persistent rumours that a deal would be struck to let him leave Pakistan before facing the courts to avoid a clash between the army and government.
But no deal has been forthcoming and last week, speaking publicly for the first time since his house arrest began, Musharraf vowed to stay and fight to clear his name.