For more than three decades Ian Paisley has been one of Northern Ireland's leading politicians.

He first attracted major public attention in 1963 when he organised a march in protest at the decision to lower the union flag at Belfast City Hall to mark the death of Pope John.

In fact, fierce opposition to the Catholic Church combined with a determination to resist the cause of Irish nationalism have always been the cornerstone of Mr Paisley's beliefs.

With his large stature and booming preacher's voice the Democratic Unionist leader is undoubtedly the most easily recognisable figure on the Northern Ireland political stage.

His opponents have always had to endure angry denunciations and accusations of betrayal. In the 1960s the moderate Prime Minister Terence O'Neil was berated as a traitor to the unionist cause.

In later years, when direct rule was imposed from London, successive secretaries of state for Northern Ireland faced similar accusations. Mr Paisley has resisted any agreement which he believed would extend the influence of the Irish Republic into the affairs of Northern Ireland.

He opposed the Sunningdale Agreement in 1973, the Anglo-Irish Agreement in 1985 and the agreement reached at Stormont on Good Friday this year.

It is clear that he will do his best to oppose any attempts to let Sinn Fein, the IRA's political wing, take up ministerial posts, or to set up cross border bodies between Northern Ireland and the Irish Republic.

Now 72, Ian Paisley remains an energetic campaigner for the unionist cause, who has a loyal and devoted following.