Personnel from the Grenadier Guards have taken part in a service of remembrance in central London.
Black Sunday is a regimental day when serving and former Grenadier Guardsmen come together to pay tribute to those killed and injured.
It took place at Wellington Barracks and the Guards Chapel before moving on to the Guards Memorial.
Captain Charlie Gilmore said: "It's a very important day - the opportunity for the serving regiment, and those who have served, to remember our dead and our wounded from conflicts past.
"It's something we take incredibly seriously.
"We think of ourselves very much as a family regiment, and that is very much true today."
The Duke of York, who is Colonel of the regiment, joined personnel and veterans in Westminster to pay his respects.
A parade took place from Wellington Barracks where both serving and former personnel marched together in memory of their fallen comrades.
They marched to the Guards Memorial by Horseguards where the Duke laid a wreath.
Captain Robbie Thompson, Equerry to the Duke of York, said:
"This is such a big year for the Grenadier Guards, with our trooping of the colour in June, but this was an occasion he really didn't want to miss."