A former top cop whose love of the monarchy saw him try to put the ‘royal’ into Britain’s biggest force has died at the age of 94.

Sir David McNee’s 36-year career in policing brought bouquets and brickbats as he faced up to a Britain riven with industrial, political and racial unrest.

As the UK’s most senior officer – holding the post of Met commissioner from 1977 to 1982 – his watch encompassed the Brixton and Southall riots in London and the dramatic siege of the Iranian embassy, all of which later led to the routine issuing of protective riot gear to officers.

But the staunch royalist remembers with chagrin an event which he later recalled as the “lowest point of my entire career” – the infamous Buckingham Palace break-in with intruder Michael Fagan found at the end of the Queen’s bed in one of the worst security breaches of the 20th century.

Fiercely proud of the old-school, non-graduate background he brought to the upper echelons of policing, the son of the Royal Scot train driver never fully recovered from the embarrassment and left the service shortly after the July 1982 incident.

Sir David, born in March 1925, had a strong religious upbringing – growing up in a Glasgow tenement.

Boys’ Brigade, trombone practice and singing tenor in the church choir, he left school at 15 to work at the Clydesdale Bank before being called up in 1943 in the Second World War – joining the Royal Navy as a telegraphist.

After being demobbed, he went into the City of Glasgow Police in 1946 as a constable and quickly established a “firm but fair” reputation that would stay with him throughout his time in the service. He switched to the force’s marine division in 1951 as a detective constable.

He rose through the ranks to inspector, serving in the Flying Squad and the Special Branch, before attending a senior command course at the Police Staff College, Bramshill, which led to a brief and successful spell as an assistant chief constable in Dunbartonshire Police and then the top job in Glasgow in 1971. Four years later, he was the first chief constable of the newly-created Strathclyde force.

Corruption scandals damaged the Met’s reputation in the 1970s and Labour Home Secretary Merlyn Rees saw the wisdom in appointing a commissioner from outside London.

Sir David was duly approached to replace the popular Sir Robert Mark in 1977 – going from the second largest force in Britain to being in charge of the largest.

The turmoil swirling around Britain in those times, and polarised in London, saw his force face a violent confrontation at a National Front rally in Southall, west London, opposed by the local Asian community and the Anti-Nazi League in 1979.

Schoolteacher and ANL activist Blair Peach was killed in the ensuing riot, for which many held the police responsible.

The force also found itself policing the long-running union dispite at Grunwick's photo-processing plant in north-west London. Police and pickets clashed on a near-daily basis, leading to mass arrests.

Tension between the police and parts of London’s black community finally erupted in the Brixton riots of April 1981, the force’s Operation Swamp being seen by community leaders as a heavy-handed response to crime in the area.

The riot resulted in almost 300 police and 45 members of the public being injured. More than 100 vehicles were burned, including 56 belonging to the police; almost 150 buildings were damaged, with 30 set on fire.

Reports suggested that up to 5,000 people were involved in the riot.

The Scarman report on the policing of racially mixed areas – and routine issuing of protective riot gear to officers – followed after around 400 were injured in the clashes.

He was applauded in 1980 for the handling of the sige of the Iranian embassy, which was taken over by six exiles demanding the release of prisoners in their country.

The SAS ended a five-day standoff, during which a hostage was murdered. Five of the six terrorists were killed.

Policing successes included “bobbies on the beat”, but the stop and search policy further aggravated already-strained community relations.

Corruption investigation Operation Countryman, which resulted in a handful of unsuccessful prosecutions of officers, proved a lengthy thorn in the side for Sir David.

The July 1982 royal break-in by the barefooted Fagan, who had psychiatric problems, caused the commissioner most distress.

Fagan was able to scale the railings of the royal building, climb unchallenged through a window and stroll up the Queen. Police back up was 10 minutes away.

At the same time the Queen’s personal protection officer, Commander Michael Trestrail, was having a relationship with a sex worker. It led to calls for Sir David to resign.

He didn’t immediately but was upset by the lack of support from the then Home Secretary, Willie Whitelaw – Prime Minister Margaret Thatcher’s deputy.

His love of all things regal saw Sir David try, but fail, to have his force renamed the Royal Metropolitan Police. But he did have the satisfaction of Princess Margaret coming to his Met leaving party in 1982 – to thank him for 36 years of loyal service to policing.

In retirement, his memoirs – McNee’s Law – suggested that criticism of the police was undeserved and the service was the “political scapegoat” for government failures to address social problems.

Free from public office, he took on directorships with his first employer, the Clydesdale Bank, and with Trusthouse Forte, Scottish Express Newspapers and Integrated Security Services; as well as acting as an adviser to British Airways.

He took on overseeing his fellow evangelical Billy Graham’s Mission Scotland crusade in 1991.

His first wife was Isabel Hopkins (1952-1997) with whom he had a daughter, Heather.

After her death, he met and remarried Lilian Campbell in 2002. He is survived by her, Heather and two stepchildren, Laura and Finlay.

Sir David died unexpectedly on April 26.