Northern Ireland-born QC Richard Ferguson, who featured in some of the most high-profile criminal cases of the last two decades, has died at the age of 73.

Among his headline-making court appearances were the trials of Rosemary West, — wife of mass-murderer Fred West — and IRA Brighton bomber Patrick Magee.

The well-known barrister, who died at London Bridge Hospital on Sunday, also appeared for Ernest Saunders in the famous Guinness trial and, among scores of other prominent actions, successfully defended two British soldiers accused of war crimes in Iraq.

His performance meant he was sought out for many plum cases, which meant he built an impressive reputation and made serious money, at the Bar.

It was once said of him: “He is God — he has the kind of voice that could read the jury a phonebook and they would listen.”

In Northern Ireland, he was both a politician and a barrister before moving to London.

Richard Ferguson was born into farming stock in Derrygonnelly, Co Fermanagh, where his father Wesley was a police sergeant. He attended Methodist College in Belfast before studying law in Belfast.

He said he was drawn to law by The Winslow Boy: Terence Rattigan's play about a young naval cadet, wrongly accused of stealing, who is cleared by the efforts of a brilliant lawyer.

According to Ferguson: “What has always driven me has been the desire to stand up for the little man and take on the powers of the state and, where possible, secure a verdict of not guilty.

“What I always wanted to do was to take on the unpopular client and to demonstrate that the popular conception of the case was wrong.”

Much of his early work was in Fermanagh where juries were notoriously thran and traditionally disinclined to convict anyone of anything.

Ferguson quickly made a name for himself, first in insurance cases and then in criminal work.

In common with several other members of the Ferguson family he went into politics, taking a seat in 1968 for the Ulster Unionist party in the then Stormont parliament.

He was a strong supporter of Prime Minister Terence O'Neill's well-meaning but ineffectual attempts to reform unionism and improve community relations. According to a Catholic contemporary: “He was personally very liberal, totally devoid of any sectarianism.”

His particular brand of moderation was not, however, appreciated by everyone and when his home was damaged in an explosion, probably caused by loyalists, he quit politics to concentrate on law. He took silk in Belfast in 1973.

As the Troubles developed he appeared before fewer juries because cases involving the IRA, loyalists, soldiers and policemen were tried in Diplock courts. He appeared for all these elements: “I am very ecumenical,” he once said. “No one was ever able to pigeonhole me.”

He departed from Northern Ireland in 1983, probably as the result of a personal crisis, and moved to London where he took silk in 1986.

At first some wondered how he would fare outside the narrow confines of Northern Ireland, but it rapidly became clear that he was destined to be a big fish in a big pool.

His cases involved property tycoon Nicholas Van Hoogstraten, Richard Branson of Virgin, Afghan airplane hijackers, the Birmingham Six, Guinness boss Ernest Saunders and boxer Terry Marsh. He regretted, he once said, not having the chance to defend Michael Jackson.

By the mid 1990s he was chairman of the Criminal Bar Association and by 2003 he was the top-earning criminal defence barrister, with more than £800,000 in that year.

A journalist wrote of one of his trials: “It takes no time to identify the star of the show. He has a powerful presence in court, as well as humour and charm, but there is a hint of danger in the air from the moment he starts cross-examination.”

Another observer wrote of him, slightly fancifully: “With his beautifully-tempered advocacy his style is not to declaim to the jury, but to seduce them with his Ulster brogue. One could almost hear the peat crackling in the hearth and smell the Black Bush whiskey as he poured scorn on the Crown's case.”

He was unusually willing to comment on cases out of court, which he did in that of Rosemary West, whom he unsuccessfully defended on 10 charges of the murder of young women and girls. Her husband Fred committed suicide before he could be tried.

Ferguson declared: “She did not get a fair trial because the media, in advance of the trial, had hyped up the situation to such an extent that no jury could have judged her case dispassionately. Fred was dead and somebody had to be held responsible. If he'd been alive she might have been acquitted.”

His toughest adversary, he said, was the late George Carman QC, whom he described as “without doubt the best advocate I have ever come across.”

He recalled: “He kept doing things which I regarded as professionally inappropriate. You had to be on your toes with George — he was regarded by the judges as a little bit naughty but very engaging.”

Ferguson was keen on walking, climbing and Arsenal football club. He was not interested in retirement, taking cases until earlier this year.

He married twice, in both cases to lawyers. His first marriage was to solicitor Janet Magowan while his second was to barrister Roma Whelan.

He is survived by ex-wife Janet, wife Roma and by four children from his first marriage, Catherine, Richard, William and James, and a son, Patrick, from his second.

The funeral service will be held at Gray’s Inn, London, on Friday morning.