By Tom Bishop
BBC News Online entertainment staff
The fact that rock singer Bono was invited to speak at the Labour Party conference confirms his rare ability to combine the duties of a pop star with those of a global campaigner.
Bono was born to a Catholic father and Protestant mother in 1960
Bono has consistently used his position as frontman of one of the most popular rock acts in the world to draw attention to human rights issues, from the need for famine relief in Ethiopia to criticising nuclear tests in France.
His high-profile meetings with world leaders such as President George Bush and Pope John Paul II followed dubious nightly attempts to telephone the White House live from U2's concert stage.
He was born Paul Hewson on 10 May, 1960, to a Catholic father and Protestant mother in Dublin.
Ireland's religious strife, and the sudden death of Bono's mother when he was 14, proved major influences on the songs he wrote for U2.
His music career began when he formed a band with guitarist The Edge (real name David Evans), bassist Adam Clayton and drummer Larry Mullen Jnr at school in 1976.
Taking on vocal duties, Hewson adopted the nickname Bono Vox, supposedly from the Latin for "good voice".
U2 in 1988, receiving one of 14 Grammy Awards in New York
The band also changed its name from Feedback to Hype to U2, and were signed to record label CBS Records Ireland after winning a talent contest in Limerick.
Releasing their first EP in 1979, early success in Ireland led to the band being snapped up by Island Records in the UK.
Critics heaped praise on their 1980 debut album Boy, supported by a series of passionate and charismatic live shows throughout Britain and the US.
In 1983 the band reached the UK Top 10 with New Year's Day, a song inspired by the Polish Solidarity Movement and the first of 25 Top 10 hits.
Third album War covered religious and political conflicts, especially in the song Sunday Bloody Sunday, before live album Under A Blood Red Sky earned U2 their first significant US chart placing.
In 1984 the band established its own company, Mother Records, to unearth fresh musical talent in Eire.
U2 at a 1992 Greenpeace protest against Sellafield nuclear plant
U2's commitment to its members' ideals was further underlined by their appearances at Live Aid, Ireland's Self Aid, and their involvement with Amnesty International.
Their 1987 release The Joshua Tree became the fastest-selling album in history, topping both the US and UK charts.
However Bono's righteously candid interviews, combined with a tendency to preach on stage, led to a press backlash against the singer's "po-faced self-mythology".
U2 responded by disappearing for two-and-half years, returning with a postmodern sense of irony and the acclaimed 1991 album Achtung Baby.
During the supporting Zoo TV stadium tour, Bono assumed the persona of a prototypical rock star called the Fly, a corrupt televangelist named Mirrorball Man and Mister Macphisto, the devil portrayed as an ageing rock god.
A regular concert feature was Bono's live attempt to contact world leaders, usually thwarted by a confused receptionist.
Bono with wife Ali Hewson and daughters Jordan and Memphis Eve
Undaunted, Bono continued to work as a social activist, protesting alongside his wife Ali Hewson against the operation of Sellafield nuclear plant in Cumbria.
Bono used his acceptance speech at 1995's MTV Awards in Paris to criticise French president Jacques Chirac's support for nuclear tests.
In 1999 he joined the Jubilee 2000 movement, later renamed Drop the Debt, dedicated to erasing the public debt of 52 of the world's poorest countries, many of them located in Africa.
As group ambassador he met with Pope John Paul II, UN Secretary-General Kofi Annan and US Presidents Bill Clinton and George W Bush, saying he and Bush had a "good old row".
Meanwhile U2 regained their popularity with the 2000 album All That You Can't Leave Behind, a return to their original epic rock sound which earned them a further four Grammy Awards to add to their 14-strong haul.
The singer had a "good old row" with President Bush in 2003
Two years later Q magazine voted Bono the most powerful figure in the global music industry for his ability to win the attention of world leaders.
With the band's 14th album - How To Dismantle An Atomic Bomb - due for release in November and calls for Bono to be considered for a Nobel Prize for humanitarianism, his influence seems stronger than ever.