When Tam Dalyell leaves the Commons at the next election, he will retire as Father of the House - the longest serving MP.
But for many he will always be known as the leader and most persistent and effective of parliament's awkward squad.
Father of the House was constant critic
It is an unofficial title the castle-dwelling Baronet attracted from virtually the day he entered parliament in 1962. And it is one he appears to relish.
He was never overly-impressed, and certainly never cowed, by authority or power, as successive prime ministers discovered to their cost.
He developed a particular reputation for his opposition to war, notably Suez, the Falklands and the Gulf conflicts.
He harried then prime minister Margaret Thatcher over the Falklands and his quote about the sinking of Argentine warship Belgrano - "but in which direction was she sailing at the time" - entered popular political culture as a way of suggesting a conspiracy at work.
It was a question, like many others, that he continued to ask long after most others had either lost interest or simply given up.
He was kicked out of the Commons chamber on a number of occasions, most notably for accusing the prime minister of lying over the Falklands war.
Dalyell questioned Belgrano sinking
Similarly he will forever be remembered as the man who persistently raised the "West Lothian Question" - named after his original constituency - about why post-devolution Scottish MPs should continue to vote in the Commons on English legislation.
He has always been linked to the left-wing of the Labour party, although he was never one to unthinkingly toe any line.
And this shambling, eccentric toff started his political life as a Tory in the Cambridge University Conservative Association, of which he became President in 1954.
The closest he came to a ministerial career was when he acted as parliamentary private secretary to cabinet minister Dick Crossman.
Even in his early years as an MP, he asked 70 parliamentary questions about plans to build a military airport on a wildlife-rich area in the Indian Ocean.
Mr Dalyell is unrepentant of the way he deals with issues he believes in, once saying: "You must not be afraid to be thought a bore."
Crossman gave him a job
The Gulf War brought particular opposition - he predicted it could set off fires that could burn for years.
His also landed in trouble with the Commons authorities when he leaked minutes of a select committee's meeting about the Porton Down defence research establishment to a journalist.
Despite his insistence that he thought the minutes were in the public domain, he was brought to the bar of the Commons to be upbraided by the Speaker.
Last year, he labelled Tony Blair the worst prime minister and Labour leader he had experienced while in Parliament.
And that is a very long time indeed.