Pop megastar Prince is to make his only European appearance this year with 21 shows in London. The singer will begin his purple reign with seven nights at the O2 Arena - formerly the Millennium Dome.

Tickets will cost just £31.21, a reference to his 3121 album. And everyone who gets their hands on a ticket will get a free copy of
his new album - a move the star dubbed his own version of "direct marketing".

The rest of the 21 Nights In London tour will include some secret club gigs.

Speaking at a launch event in London, Prince declared himself a fan of Amy Winehouse and said he hoped she would join him on stage.
He has prepared 150 songs and will play a selection at each show - likely to include his hits Purple Rain, When Doves Cry and Kiss.

The tour, which begins on August 1, will be Prince's only appearance in Europe this year. Explaining why he chose the UK, Prince said: "I love London. I've had some of my favourite shows here."

The star is now house-hunting in the capital. "As soon as I leave here I'm going to look for a place to live," he said. Of the rock-bottom ticket prices, he said: "Last time I was here a lot of people didn't get to see me so we are trying to make it affordable for everybody. That's why we are doing an extended stay."

Prince announced the tour at a press conference held in The Hospital private members club in Covent Garden, central London. The 48-year-old star wore a white suit and shades for his brief appearance, in a darkened room lined with purple drapes.

This will be the first time he has played a UK arena in over a decade. The singer expects his most devoted fans to attend more than one gig. "There are going to be so many nights here that we are going to change the show every night," he said.

"We play so many different styles of music, it's really hard to get a full dose of what we do unless you come to several shows. "Also I have a wide fan base that come to multiple shows, I see that a lot in London."

Revealing his current music tastes, he said: "I love the song Love Is A Losing Game by Amy Winehouse. I'm hoping that she's going to show up to one of the gigs. I'm a big fan."

He also promised a version of Beatles hit The Long And Winding Road. All fans buying a ticket will receive a free copy of his new album. "It's direct marketing. I don't have to be in the speculative business of the record industry," he said.

Prince has returned to being called "Prince" after a spell which saw him change his name to a squiggle. He was referred to as The Artist
Formerly Known As Prince during a contractual wrangle with his record label.

A Jehovah's Witness for several years, Prince said he would not be playing any other European dates this year because he must devote time to studying the Bible.

Prince is one of the world's most successful recording artists. He has sold 80 million albums in a career which has earned him six Grammys, six Brits and one Oscar. In February he gave a storming half-time performance at the Superbowl
in the US, and last year began a weekend residency at the 3121 club in Las Vegas.

Prince also stole the show at the 2006 Brit Awards at Earls Court. Speaking of his plans to find a home in London, he joked: "My favourite place is Earls Court, but I can't live there."

Tickets for the O2 gigs go on sale at 9am on Friday from www.aeglive.co.uk, www.3121.com or www.marshall-arts.co.uk.

Prince's low ticket prices contrast with those of other US stars. Barbra Streisand is charging £100-£500 for seats in the same venue.