Byron's bisexual secrets were kept from biographer, exhibition reveals

The first big exhibition on Lord Byron for 30 years will show that documents on the Romantic poet's affairs with young men were withheld from his biographer, Leslie Marchand, in the 1950s.

Mad, Bad and Dangerous, taking its name from Lady Caroline Lamb's description of her erstwhile lover, opens at the National Portrait Gallery in London on Wednesday. As well as documenting his bisexuality, it will also explore Byron's self-promotion in the light of contemporary culture.

With a surge of interest in the poet, who died in exile after fighting for the Greeks against Turkish rule, the organisers aim to show Byron was the forerunner of writers, performers and artists skilled in the art of self-promotion.

Fiona MacCarthy, author of the first full biography of Byron since Marchand in 1957 and curator of the exhibition, said much more was known about Byron than at the time of the British show at the V&A Museum in 1974. Much is based on documentation not made available to Marchand.

Ms MacCarthy said that Byron's bisexuality added a piquancy to how he used paintings and engravings to promote himself as a hero of the Romantic movement.

"The portraits and engravings were all part of his marketing operation. You can see the whole image of celebrity, that I think people find fascinating now, in Byron – the way he helped create his own image, the way he needed fame and yet he found it agony," she said.

Bisexuality was frowned upon by society and was therefore omitted from the creation of the Byron legend, she said. When allegations of sodomy circulated, thanks to Lady Caroline, Byron was forced to flee the country.

The flurry of interest in Byron stretches beyond the Portrait Gallery, whose exhibition runs until 16 February. The BBC has announced a television drama on Byron starring Jonny Lee Miller.