Police officers and staff who died on duty have been commemorated in a monument that has been unveiled at the National Memorial Arboretum.
The Prince of Wales was among those at a dedication ceremony at the £4.5m memorial and garden created at the Staffordshire site, where a minute's silence was held.
He paid tribute to the "valour and sacrifice" of those who had died.
The UK Police Memorial is the result of a six-year fundraising campaign.
It is designed to look like a giant door, which is slightly ajar, and represents the threshold across which police officers step every day into potential danger.
The Police Arboretum Memorial Trust said since an early incarnation of police were set up in 1749, almost 5,000 officers and staff had died on duty - 1,500 from acts of violence.
Prince Charles expressed thanks on "behalf of the nation".
"Our expressions of appreciation will always be hopelessly inadequate and, unfortunately, make the anguish no easier to bear," he said.
"I do pray that this memorial will not only provide a hallowed place for us all to pay tribute to each of them, but also the reassurance that those who have given their lives so selflessly will leave a lasting legacy and will never be forgotten."
The new 39ft-tall (12m) memorial includes two low screens bearing the names of 2,000 police officers and staff, along with spaces for reflection, and is larger than the existing national tribute in central London.
Sir Hugh Orde, chair of trustees of the UK Police Memorial, said: "I think its great strength is its simplicity. It recognises the dangerous space through which police officers go every day of their working lives to protect citizens."
The arboretum at Alrewas, which is home to about 400 different memorials on its 150-acre site, offers a national, year-round focus for remembrance, organisers said.
Families of police officers who have been killed on duty were among the invited guests on Wednesday, as was Prime Minister Boris Johnson, Home Secretary Priti Patel, Metropolitan Police Commissioner Dame Cressida Dick, chief constables from forces across the country and representatives from policing charities.
Readings were given by bereaved relatives, including Gillian Wombwell, whose husband David was shot dead alongside two colleagues in London in 1966
She said the memorial "may have been a long time coming" but was "just phenomenal".
The fathers of police officers Fiona Bone and Nicola Hughes, officers who were murdered in a gun and grenade attack, officially marked the start of work on the site last year.
The monument itself has been designed by Walter Jack, while the surrounding landscape that makes up the rest of the memorial was designed by Charlotte Rathbone.
Visiting ahead of Wednesday's ceremony were 10-year-old Harvey, five-year-old Riley, and seven-year-old Reggie. Their grandfather, Mac Walker, a West Midlands Police traffic officer, was killed in 2001 after being deliberately rammed off his bike in Birmingham by a man driving a stolen car.
Mr Walker's widow, Helen Walker, said the memorial was "in a lovely location".
She added: "It's a place where children, grandchildren and future generations can come and honour their heroes and the courageous sacrifice the fallen officers have made to protect the public."
The memorial complements an existing digital memorial to police workers who have died while on duty.