London - Flag-waving crowds of Britons lined the streets and politicians proffered gushing praise as Queen Elizabeth launched a nationwide tour of her realm on Thursday to celebrate 60 years as monarch.
Elizabeth's four-month tour will take in England, Wales, Scotland and Northern Ireland, as part of celebrations for her reign which began on February 6 1952.
It starts in Leicester in central England, where the 85-year-old monarch will travel by train with her husband Philip and Catherine, the wife of grandson Prince William, for a visit to a university, cathedral and the city centre.
Millions of Britons
"The excitement and anticipation felt around our campus since this visit was announced is a measure of the great affection our students and staff have for the queen," said Dominic Shellard, the vice-chancellor of De Montfort University.
"This special celebration will be history in the making, not just for De Montfort University, but for the people of Leicester, and I have no doubt memories of this occasion will be cherished, for years to come, by everyone who witnesses it."
The focal point of the diamond jubilee festivities will take place over four days in June, including a 1 000-ship pageant on the River Thames through London and a concert at Buckingham Palace.
Millions of Britons thronged the streets of London for celebrations to mark her 50th year on the throne in 2002 and organisers expect a similar reaction this summer.
Other members of the royal family are also taking part in a global tour of major Commonwealth countries and realms where Elizabeth is head of state, with grandson Prince Harry, William's younger brother, currently in the Caribbean.
Elizabeth has overseen some tumultuous times since she became queen on the death of her father George VI in 1952.
She has presided over the continued dismantling of a centuries-old British empire which spanned the globe under her father, bid farewell to former colonies such as Kenya, Jamaica and Hong Kong, seen the marital indiscretions of her children skewer the royal family's popularity at home, and witnessed an unprecedented outpouring of public grief over the deaths of her divorced daughter-in-law Diana and her mother - the last British queen to hold the title Empress consort of India.
Republic, a group that opposes the monarchy, has promised to hold protests during the jubilee celebrations.
The popularity of the royal family has been revived of late with the telegenic good looks and easy charm of Diana's son William, a dashing future king who married his long-time girlfriend last year in a glittering ceremony at Westminster Abbey that was watched by some two billion people on television.
'A point of light'
"While the sands of culture shift and the tides of politics ebb and flow, her majesty has been a permanent anchor, bracing Britain against the storms, grounding us in certainty," Prime Minister David Cameron told parliament on Wednesday.
"Diamond is the appropriate epithet for this jubilee. For 60 years, Her Majesty has been a point of light in our national life - brilliant, enduring and resilient," he added in a "humble address" on behalf of all lawmakers.
"For that, she has the respect of the House and the enduring affection of all her people."
Parliamentarians from all parties joined the effusive praise, heralding all aspects of her life from her professionalism and dedication to public duty to her looks.
"For my generation, the abiding memory of our queen is her stunning beauty when she came to the throne," said Sir Peter Tapsell, the oldest member of the House of Commons at 82.
"There is nothing more inspiriting in the whole world than a beautiful woman."