Richest prize pits Churchill against geese

Judges will compare accounts of the life of Winston Churchill, the migration of snow geese and the naming of clouds to decide this year's winner of the £30,000 Samuel Johnson prize for non-fiction.

The other contenders on the six-strong shortlist announced today are the story of a 16th-century English village, an analysis of Britain's role in Bosnia and the story of the 1919 Paris peace conference.

The prize, the most valuable in Britain for non-fiction, will be awarded on 24 June at a dinner in London. The judges include the broadcaster David Dimbleby, who is chairing the panel, the scientist Richard Fortey and the writer Robert Harris.

At least half the books follow in the heavyweight tradition of the first three years of the prize, when the winner's cheques were received by Antony Beevor for Stalingrad, David Cairns for his biography of Berlioz and Michael Burleigh for his history of the Third Reich. Politics dominate with a politician, Roy Jenkins, leading the way with his well-received life story of Churchill, from childhood through his parliamentary career to his status as elder statesmen.

Peacemakers by Margaret Macmillan, a professor of history in Canada, looks at the conference that concluded the First World War and argues that the three Allied leaders, Woodrow Wilson, Lloyd George and Georges Clemenceau, have been unfairly scapegoated for the role of the Treaty of Versailles in causing the Second World War.

Unfinest Hour, by Brendan Simms, a Cambridge academic, looks at the war in Bosnia and the world's response to it, asking whether the British Government helped to prolong the conflict.

However, the judges will get some light relief from the other volumes in the running.

The Invention of Clouds, by Richard Hamblyn, is the true story of Luke Howard, an amateur meteorologist who classified the clouds in 1802. This was an important moment in meteorology and it also made him a cult figure for Romantics such as the poets Coleridge and Shelley.

The Snow Geese, a first book by William Fiennes, blends autobiography, reporting and natural science to follow the journey of migrating snow geese home to the Canadian Arctic and discuss the nature of homecomings.

The final contender is The Voices of Morebath: Reformation and Rebellion in an English Village, by Eamon Duffy, the president of Magdalene College, Cambridge. It uses written accounts of an early 16th-century country priest, Sir Christopher Trychay, to give an account of the social life of a pre-Reformation village.