A history of the Italian poet Gabriele D'Annunzio, who tried to set up a fascist state in Italy in the early 20th century and was an influence on the dictator Benito Mussolini, won Britain's Samuel Johnson Prize for Nonfiction on Monday.

Author Lucy Hughes-Hallett's The Pike focuses on the life of "the debauched Italian artist who became a national hero," the prize committee said in a statement.

"Through his ideological journey, culminating in the failure of his attempt at Fiume to establish a utopia based on his fascist and artistic ideals, readers witness the turbulence of early 20th-century Europe and the emergence of fascism, while also allowing a personal story of an outrageous career," the committee said.

The prize, which is given for nonfiction writing in English, is in its 15th year and carries a 20,000 pound ($31,800) award.

Martin Rees, chair of the judges and Royal Astronomer, said readers of Hughes-Hallett's book "will be transfixed by her vivid portrayal of D'Annunzio - how this repellent egoist quickly gained literary celebrity - and how, thereafter, his incendiary oratory, and foolhardy bravery influenced Italy's involvement in World War I and the subsequent rise of Mussolini."

Hughes-Hallett is the author of two previous books, Cleopatra: Histories, Dreams and Distortions and Heroes: Saviours, Traitors and Supermen.

Wade Davis was last year's winner for his account of George Mallory's ill-fated attempt to scale the heights of Mount Qomolangma.

Reuters