Grief-stricken former Beatle Sir Paul McCartney was in mourning on Monday at his southern England home after the death from cancer of his American wife Linda at the age of 56.

McCartney, who had spent only one night apart from Linda in their 29-year marriage, was described by friends as "shipwrecked."Linda McCartney died in Santa Barbara, Calif., on Friday after the breast cancer diagnosed in 1995 spread to her liver last month.

"Paul is absolutely shipwrecked but his bravery is astonishing. He told me, `We will never get over it, but we will have to get through it.' He is surrounded by his children," television writer and close friend Carla Lane told The Sun news-paper.

McCartney was closeted in the farmhouse home in Sussex, which he shared with Linda and from which she built up a successful vegetarian food business.

The couple's three grown children - Mary, Stella and James - were with him. His spokesman appealed for privacy, saying McCartney would not be making any statement until Thursday.

McCartney was at his wife's bedside when she died. The couple had been out horse-riding only two days before.

"The blessing was that the end came quickly and she didn't suffer. Anyone who knows the family knows how close and loving they are. So this is a devastating blow to all of them, and they have asked to be left in peace to grieve in private," McCartney's spokesman, Geoff Baker, said.

McCartney has asked that instead of sending flowers, people could make a donation to cancer research or animal welfare charities - or simply "go veggie (vegetarian)," his office said.

Funeral arrangements have not been made public.

Linda McCartney was a lifelong vegetarian who developed her own line of vegetarian foods. She was also a lover of animals, photography and music.

Throughout their life together she photographed her husband, campaigned with him for various causes and made music with him - from his immediate post-Beatle days to his most recent album "Flaming Pie," in which they sang on some tracks together.

Tributes poured in Monday to the woman who drove Beatles fans to tears when she married McCartney in March 1969. She was an American socialite photographer; he the singer-songwriter in the most famous pop band in the world.

After the break-up of the Beatles, Linda joined McCartney's new band Wings, as a keyboard player and backing singer and braved taunts that she could neither play nor sing.

Their hits included the best-selling album "Band On The Run." The group's single "Mull of Kintyre," recorded in 1977, is one of the world's biggest selling singles.

Former Wings drummer Denny Seiwell said the pair were in-sep-a-ra-ble.

Linda had thought she had beaten the breast cancer, telling an interviewer only two months ago. "I'm back."

She told Britain's OK magazine that she and McCartney were like lovestruck teenagers.

"We're doing those little things together that you do when you're first dating - going to the theater or just walking hand in hand through the fields," she said.

British Prime Minister Tony Blair, who was traveling in Jerusalem when the death was announced on Sunday, said, "Linda showed extraordinary courage throughout her illness. She made a tremendous contribution across a whole range of British life."