A dream in Dior: Miss Swinton on the red carpet

But after the 47-year-old actress took her younger lover to the Baftas - leaving her long-term partner in Scotland looking after the twins - she will have doubtless raised a few more.

Miss Swinton was named Best Supporting Actress at the ceremony, making her a hot favourite for an Oscar.

But as she celebrated after the awards on Sunday, it was hard to tell whether onlookers were inspecting the golden trophy - or the 29-year-old companion who carried it.

It was the first time Miss Swinton, who wore a Dior gown, had showed off Sandro Kopp in public.

The German artist escorted her to the dinner held after the awards at the Grosvenor House hotel in London and remained with her until the early hours.

Meanwhile, 68-year-old John Byrne, her partner of 18 years, stayed at home in the north of Scotland, looking after the couple's ten-year-old twins Xavier and Honor.

Last month Miss Swinton finally spoke about the couple's complicated relationship, following a spate of rumours on the internet.

She described Mr Byrne, a director and artist, as a "phenomenal father" and said: "We are the best of pals and adore being parents and are devoted to that project.

"We ostensibly live in the same house, but I travel the world with another delightful painter."

Mr Byrne, who began his relationship with Miss Swinton in 1990, appeared to agree: "We're amicably living together in the same house, under the same roof. It's extraordinary.

"We love each other too, in an extraordinary way. We have always been the best of chums and will remain the best of chums for the rest of our lives.

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Two's company: Tilda Swinton arrives at the Baftas with Sandro Kopp

"We love our children and our children love us. The rest is business." Miss Swinton met Mr Byrne in 1985. He had designed the set of a play she was appearing in at the Traverse Theatre in Edinburgh.

Five years later they fell in love when she played the stroppy, butch cowgirl in Your Cheatin' Heart, the follow-up to his acclaimed TV series Tutti Frutti, which was set in the Fifties.

At home: John Byrne, the long-term partner

Mr Byrne left his wife and the couple set up home in London, before moving to Tain and later to Nairn, near Inverness.

Mr Kopp, who describes himself as a travelling painter with bases in New York, Paris, Germany, New Zealand and Rome, met Miss Swinton when he worked on The Chronicles of Narnia, both as a performer and as a visual artist. She took on the role of the White Witch for the films.

Miss Swinton had a privileged education, attending West Heath Girls' School in Sevenoaks, Kent, where Princess Diana was a pupil.

The actress later went to Fettes College in Edinburgh, where Tony Blair was a pupil, before studying at Cambridge.

Her big break came in 1992, when she took the title role in the art-house hit film Orlando.

And in 2000 she achieved Hollywood fame when she appeared alongside Leonardo DiCaprio in The Beach.