Jackson is one of the most successful recording artists of all time

Michael Jackson, one of pop music’s biggest stars, is expected to announce his comeback with a series of concerts at London’s O2 arena.

Here are the ups and downs of the 50-year-old singer’s lifetime in pop.

Michael, the seventh of nine children, joins his brothers’ pop group in 1964 - initially playing tambourine and bongos.

MICHAEL JACKSON - THE FACTS Full name: Michael Joseph Jackson Born: August 29, 1958, Gary, Indiana, US Also known as: The King of Pop, Wacko Jacko Biggest hits: I Want You Back, Don’t Stop Til You Get Enough, Billie Jean, Bad, Black or White, Earth Song

He quickly becomes the centre of attention and takes on lead vocal duties as the band build up a reputation on the live circuit.

Motown acts Gladys Knight and Bobby Taylor recommend the Jackson Five to their boss Berry Gordy. The groups’ first release on the legendary Detroit label, I Want You Back, goes straight to number one in 1969 - when Michael is just 11 years old.

Over the next six years, the band churns out a string of hits including ABC, The Love You Save and I’ll Be There.

The Jacksons decide to leave Motown for a more lucrative deal at CBS Records. Motown sues the band for $20 million (£10 million).

Off The Wall only won one Grammy, spurring Jackson on to greater things

Jackson meets music producer Quincy Jones on the set of The Wiz - an urban retelling of The Wizard of Oz in which the singer plays the scarecrow.

He asks Jones to produce his new solo record - and the result is disco classic Off The Wall.

It sells 10 million copies, and contains hit singles Don’t Stop ‘Til You Get Enough and Rock With You.

The video for Thriller was inspired by American Werewolf in London

Jackson unleashes his pop masterpiece, Thriller, which re-writes the rule book on how pop is marketed, not least because of its ground-breaking video clips.

The record is frequently named the biggest-selling album of all time , shifting 65 million copies, according to the Guinness Book of World Records.

As the album spawns hit after hit - seven of its nine tracks make the charts - Jackson appears unstoppable. He causes jaws to drop around the world when he debuts the Moonwalk at a Motown television special in 1983.

Then, against the advice of his managers and record label, he convinces director John Landis to transform him into a zombie and a werecat in the 14-minute video for Thriller - at a cost of $500,000 (£250,000). The scale and ambition of the clip have often been copied, but never bettered.

Bubbles the chimpanzee was one of Jackson’s more famous playmates

As he films a Pepsi commercial in front of an audience in Los Angeles, Michael’s hair is set on fire by a pyrotechnic explosion. He is carried out of the building on a stretcher, and sales of Thriller jump by 150,000 week on week.

As Jacko-mania reaches fever pitch, tabloid stories about the secretive star begin to circulate. It is claimed that he sleeps in an oxygen tent and wants to buy the remains of Elephant Man Joseph Merrick.

The "Wacko Jacko" name is coined soon after, and the star retreats into his newly-purchased Neverland ranch, complete with zoo and fun fair.

Meanwhile, Jackson continues to prove his business acumen, securing the publishing rights to the Beatles’ back catalogue for $47.5 million and beating a bid from his old friend Paul McCartney.

The Bad tour gave Sheryl Crow her big break - as Jackson’s backing singer

Martin Scorcese’s video for Bad sees Michael with distinctly lighter skin, leading to rumours of plastic surgery and skin bleaching. But the press coverage does nothing to hurt the megastar’s popularity and the Bad album sells more than 30 million copies.

The success of the album kick-starts Jackson’s first solo tour. The critically-acclaimed Bad concerts feature magic tricks, lasers, and a section where the star "flies" above the audience on a crane. Prince Charles and Princess Diana attend one of the seven sell-out shows in Wembley.

As the tour draws to a close, Jackson pens his autobiography, revealing: "I’m one of the loneliest people in the world” and releases the Moonwalker film – a mixed bag of music videos and child-like fantasy sequences.

Dangerous went straight to number one on its release

With hip-hop in the ascendancy, Jackson employs urban producer Teddy Riley to give a rougher edge to his new album, Dangerous. Fans and critics alike are put off by the harsh rhythms and sparse arrangements, but it contains several hits - including Black and White, Remember The Time and the tabloid-baiting In The Closet.

While promoting the album, Jackson invites Oprah Winfrey to his Neverland Ranch for a special edition of her TV show. Beamed live around the world, the star addresses several of the stories about his private life.

He reveals that he was bullied by his father, had plastic surgery twice, and that his changing skin tones were the result of a "disorder that destroys the pigmentation of my skin".

The family of 11-year-old Jordy Chandler accuse Jackson of molesting their son. The star categorically denies the charges, but Los Angeles police raid his home while he is on tour in the Far East.

He later comes to an out-of-court settlement with the family for an estimated $20m.

The following year, Michael marries Lisa Marie Presley in what many assume is an attempt to repair his tarnished public image. The couple divorce 19 months later.

Jackson’s performance at the Brit awards was magnificently over-the-top

His crown having slipped somewhat, the King of Pop positions several giant statues of himself around Europe to promote a new album, HIStory, which combines a CD of greatest hits with a disc of new material, much of which is a vitriolic response to the star’s recent woes.

The following year, he appears at the Brit Awards to perform number one single Earth Song. The show sees Jackson surrounded by children, adopting a messianic pose which prompts Pulp frontman Jarvis Cocker to storm the stage.

Jackson declares himself "sickened, saddened, shocked, upset, cheated and angry" by the incident.

In 1997, Jackson is inducted to the Rock and Roll Hall of Fame and, in a surprise move, marries nurse Debbie Rowe, who is pregnant with his child, Prince Michael.

The couple have a daughter, Paris Michael Katherine, the following year before divorcing in 1999. The singer retains custody of the children.

Rolling Stone said the Invincible was "full of grandiose desperation"

Six years in the making, Jackson’s next album, Invincible, barely lasts six weeks on the charts.

Only one single, Rock My World, gets a full global release. Jackson blames the lack of promotion on the fact he had decided not to renew his contract with Sony – and launches an attack on label boss Tommy Mottola, calling him "devilish" and accusing him of racism.

Meanwhile, the singer’s personal life continues to cause controversy. He draws scathing criticism when he dangles the 11-month-old Prince Michael II (or Blanket) from the window of a German hotel.

On a TV documentary he admits sharing his bed with children. "Why can’t you share your bed?” he protests. "That’s the most loving thing to do, to share your bed with someone."

Police denied claims that Jackson was "roughly manhandled" on his arrest

Police raid Jackson’s Neverland ranch and, shortly afterwards, a warrant is issued for his arrest on charges of molesting a 14-year-old boy, Gavin Arvizo.

The star surrenders himself to police and is arrested and handcuffed. A five-month trial in 2005 ends with Jackson found not guilty on all charges.

Following the trial and amid rumours of bankruptcy, the elusive pop star moves to Dubai.

Jackson is expected to announce his comeback concerts at the O2 later while posters have already appeared on the London Underground advertising 10 shows there in July.

His visit to the UK follows the "amicable settlement" that was reached at London’s High Court in November 2008 with the King of Bahrain’s son, who was suing him for £4.7m, claiming he reneged on a music contract.

Jackson had been due to fly in to give evidence at the High Court before a confidential agreement was reached with Sheikh Abdulla Bin Hamad Bin Isa Al-Khalifa.

Compiled by BBC Entertainment reporter Mark Savage