He was educated in Switzerland and then at Stowe School, where he refused to join the Officers' Training Corps until World War II had broken out in September 1939.

[1] In 1945 he was awarded the Distinguished Flying Cross for his skill and valour attacking Imperial Japanese Army lines of communication within occupied Burma.

[1] Montague Browne was second secretary in the Chancery (political section), responsible for monitoring North Africa, covering Egypt to Tangier.

[1] In September 1952, Montague Browne was chosen to be Private Secretary for Foreign Affairs to the Prime Minister, Winston Churchill.

[1] As well as his duties as a chief of staff, Montague Browne lunched and dined with Churchill and provided an opponent for his favourite card game, rubicon (six pack bezique).

In 1988 he made an extended appearance on the television discussion programme After Dark alongside among others David Irving, Lord Hailsham and Jack Jones.

Montague Browne's memoir of his time with Churchill, published originally in 1995,[9] offered further affectionate, if carefully discreet, insights into the statesman's final years.

They were also 11th cousins twice removed, by their shared descent from James V of Scotland: Sir Anthony by the king's mistress, Euphemia Elphinstone, and Jane by his second wife, Mary of Guise.

In a personal statement released by Justin Welby in 2024 it was revealed that Montague Browne's great-great-grandfather, Sir James Fergusson, 4th Baronet (1765−1838), owned slaves on his plantation in Jamaica and received compensation from the British Government in 1837 following the abolition of slavery.