On July 7, 2005, four homegrown extremists detonated suicide bombs across London at Aldgate Station, Edgware Road, King’s Cross and Tavistock Square, killing 52 people and injuring hundreds more.
The city is holding several events to mark the anniversary, with members of the royal family expected to join those directly affected at commemorations.
The king urged people to draw on the “extraordinary courage and compassion” shown following the attack.
“We remember with profound sadness the 52 innocent people who were killed in senseless acts of evil – and the enduring grief of their loved ones,” he said in a statement published by the Press Association.
“In doing so, we should also remember the countless stories of extraordinary courage and compassion that emerged from the darkness of that day.
“The selfless bravery of our emergency services, transport workers, and fellow citizens who rushed towards danger to help strangers reminds us of the very best of humanity in the face of the very worst.”
‘We stood together’
“Those who tried to divide us failed,” said Starmer in a statement.
“We stood together then, and we stand together now – against hate and for the values that define us of freedom, democracy and the rule of law.”
“We honour the courage shown that day – the bravery of the emergency services, the strength of survivors, and the unity of Londoners in the face of terror.”
The Duke and Duchess of Edinburgh will attend a National Service of Commemoration at St Paul’s Cathedral and survivors and the families of the victims will hold a service at the memorial to them in Hyde Park.
Charles said that “while the horrors will never be forgotten”, the country “may take comfort from the way such events rally communities together”.
“It is this spirit of unity that has helped London, and our nation, to heal,” he said.
“Let us therefore use this 20th anniversary to reaffirm our commitment to building a society where people of all faiths and backgrounds can live together with mutual respect and understanding.”
Speaking ahead of the anniversary, interior minister Yvette Cooper warned that Islamist and right-wing extremism remained the country’s most significant threats.