British author Mervyn Peake, pictured in 1946, died in 1968, leaving behind his legendary Gormenghast trilogy. A fourth book, written by his wife, will be released in 2011. (Raymond Kleboe/Picture Post/Hulton Archive/Getty)

Random House says it has won the rights to publish the fourth book in the acclaimed fantasy Gormenghast book series by the late author Mervyn Peake.

The completed manuscript of Titus Awakes — finished by Peake's wife, Maeve Gilmore — was discovered in January by their granddaughter, triggering a publishing house bidding war.

Peake died in 1968, leaving behind a legacy of books: Titus Groan, Gormenghast and Titus Alone — all classics in the fantasy genre and highly popular. The trilogy chronicles the adventures of the 77th Earl of Groan Titus in his gothic castle Gormenghast.

In the third book, Groan had left his castle and embarked on a journey into the world. After Peake's death, Gilmore, who was also a writer, began writing a fourth book based on her husband's notes.

She died in 1983, leaving the manuscript in a box that was hidden in a south London attic until the couple's granddaughter, Christian, unearthed the pages while cleaning out the house in January.

Vintage, an arm of Random House, will publish the book in July 2011, marking the centenary of Peake's birth. It will also be releasing a new edition of the Gormenghast trilogy with 60 never-before-seen illustrations by Peake.

Peake's son Sebastian Peake has said the fourth novel, which follows Groan as he searches for a final home, contains "an eloquent finale."

In January, Sebastian told The Guardian newspaper that as he read the four exercise books with his mother's handwriting, "it gave me a real kick in the solar plexus…it's highly poignant."

Sebastian's sister, Clare Penate, is also penning a memoir about her life with their parents.