Services have been held in memory of the 52 people who died in the London Tube and bus bombings of 7 July 2005.
A minute's silence was observed as survivors of the attacks and relatives of the victims gathered for a ceremony at St Paul's Cathedral.
After the silence, petals fell from the dome and the Bishop of London spoke of the "ocean of pain" caused by the bombings.
Prince William laid flowers at the Hyde Park memorial to those who died.
The Duke of Cambridge joined victims' families, survivors and ambulance and fire brigade employees who were working 10 years ago, for the tribute of songs and personal readings.
The memorial, which consists of 52 stainless steel pillars, was designed to symbolise the random nature of the loss of life.
"It was and still is very much a part of my growing up, my childhood, my adolescence," said Emma Craig, who was 14 when she survived the blast at Aldgate.
"Quite often people say 'It didn't break us, terrorism won't break us'. The fact is, it may not have broken London, but it did break some of us."
But Paul Dadge, who was photographed helping a survivor in the aftermath of the attack at Edgware Road station, said the terrorists would never win.
"They won't beat us because there is no point at which we will simply surrender to terrorism," he said.
"That's not the spirit we saw on 7 July. That's not the spirit we've ever seen. That's not the spirit we will ever see."
At St Paul's the Bishop of London, the Right Reverend Richard Chartres, said the attacks had affected people from all over the world.
"Soon after 7 July, the families and the friends of the victims compiled a book of tributes. It is a taste of the ocean of pain surrounding the loss of each one of the victims," he said.
"The tribute book is also very revealing about the character of the London which the bombers attacked. The majority of the victims were young - they came from all over the UK, all over the world.
"London is an astonishing world in a city. But beyond the diversity, the book also conveys a unifying, agonised outcry."
Candles representing the site of each incident were carried by people who helped deal with the immediate aftermath of the attacks including George Psaradakis, who was driving the bombed bus at Tavistock Square, and Dr Peter Holden, who provided urgent treatment at the scene.