Prince Charles to visit Belfast today for National Police Memorial
The Prince of Wales is to attend National Police Memorial Day for officers killed on duty.
Home Secretary Theresa May is also taking part in the event, to be held at the Waterfront Hall in Belfast.
Sergeant Joe Holness, who founded the commemoration, said: "It brings together police forces, officers, colleagues, friends and family from across the country to remember and give recognition to those that have made the ultimate sacrifice protecting us.
"It is a day that is as profound now as it was 11 years ago when this event first started."
Charles is the patron of National Police Memorial Day, which was inaugurated by Sgt Holness after his colleague was killed on duty.
Mrs May said: "Police officers go to work every day knowing that they could find themselves in danger, and sometimes they risk their very lives as they protect the public.
"We owe a debt of gratitude to officers across the country who show bravery as a matter of course and in many cases while they are off duty.
"I am honoured to take part in National Memorial Day and to commemorate the police officers who have fallen."
Steve White, chairman of the Police Federation of England and Wales, said it was a poignant and significant day for the policing family as officers throughout the UK gather to pay tribute to fallen colleagues.
"Their dedication to duty and self-sacrifice will never be forgotten," he said.
Association of Chief Police Officers (Acpo) president Sir Hugh Orde said those who have given their lives in service to their communities must not and will not be forgotten.
"National Police Memorial Day gives us the opportunity to come together and remember those officers who put public service above their own safety, making the ultimate sacrifice for their bravery."
Services have been held all over the United Kingdom to reflect the national contribution made by the police, organisers said.
The inaugural service was held at St Paul's Cathedral on Sunday October 3, 2004.