The hotel, which claims to have invented the tradition of the afternoon tea, was opened by the Prince of Wales - later Edward VII - on 10 June 1865.
It became renowned for what were at the time luxury touches, such as electric lighting and hydraulic lifts.
Over the years, the Langham has played host to many notable guests, including the exiled French emperor Louis-Napoleon III, Charles Dickens, one of the "Cambridge Five" spies Guy Burgess and his wartime employer, the BBC.
The hotel sought to attract well-heeled guests and ensured staff members were immaculately dressed at all times. The five men pictured above were waiters.
During World War Two much of its regular clientele decamped to the countryside but the building in Regent Street remained open and served as a first-aid point and military post.
On 16 September 1940 it came under intense fire from Luftwaffe raiders who destroyed a large section of the west wing.
As the Langham was so close to the BBC's Broadcasting House, across the road at Portland Place, it was in constant danger from German bombers.
The BBC's wartime staff used to broadcast from the roof of the Langham, in particular the US correspondent Edward Murrow.
JB Priestley was also a guest in this period to be close to Broadcasting House for his frequent late-night transmissions of Britain Speaks to North America.
In 1941 the notorious Soviet spy Burgess was involved in what became known as the "Langham incident". An internal memo from his wartime employer the BBC revealed that he tried to break down the door of his room when he could not get in.
It was some time after the war was over before the Langham could be returned to its original splendour.
In 1965 the BBC took out a partial lease and made the bar the home of the BBC's private members club.
The royal suites were used for office printing and the grand ballroom became the registry.
The Langham was eventually returned to its original use after significant refurbishment.
Today, the hotel is still capable of attracting the well-heeled guests it could in its Victorian heyday when the likes of Dickens, Sir Arthur Conan Doyle and Oscar Wilde would grace its corridors.
More recently, the hotel has played host to the England cricket team, with bowler Stuart Broad claiming the building was haunted.
Broad told the Mail on Sunday how the taps in the bathroom came on for no reason and turned themselves off, leaving him "really freaked out".

Taylor, 27, is taking an indefinite break from cricket after suffering with anxiety and panic attacks.
New Zealand all-rounder Amy Satterthwaite will captain the side in Taylor's absence.
Six Super League teams will play 15 Twenty20 matches in a round-robin tournament that begins on 30 July.
Billed as London's first "Grand Hotel", it is exactly 150 years since the Langham began serving the whims of the rich and famous.
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England wicketkeeper-batter Sarah Taylor will not appear for Lancashire Thunder in the inaugural edition of the Super League.