House of Commons Speaker Sir Lindsay Hoyle has switched on Parliament's historic Ayrton Light to commemorate the moment his predecessor did the same thing 80 years ago towards the end of the Second World War.
The light which sits above the Big Ben bell at the top of the Elizabeth Tower, was switched off at the outbreak of war in 1939 to comply with blackout regulations.
The rules were aimed at reducing any light which could help Germany bombers find their targets.
In 1945, then Commons Speaker Col Clifton Brown interrupted a parliamentary debate to tell MPs that after five years, seven months and 23 days, he was turning the light back on.
Addressing the Commons, Clifton Brown said: "I pray that with God's blessing, this light will shine henceforth not only as an outward and visible sign that the Parliament of a free people is assembled in free debate, but also that it may shine as a beacon of sure hope in a sadly torn and distracted world.'
