British Prime Minister Winston Churchill, U.S. President Franklin Roosevelt and Soviet Premier Josef Stalin are shown at Yalta, Crimea, in this Feb. 4, 1945, file photo. The Roosevelt and Churchill archives are to be made available online. (Associated Press)

Archives for two of the Second World War's great leaders — British prime minister Winston Churchill and U.S. president Franklin Delano Roosevelt — are to be made available online.

The Franklin D. Roosevelt Presidential Library plans to put 5,000 of FDR's papers online and British publisher Bloomsbury will post more than one million of the former British prime minister's papers.

The documents include a few surprises, such as the handwritten letter from fascist Italian dictator Benito Mussolini congratulating FDR on his inauguration and a note from a woman who had a brief affair with him in 1918.

Churchill's papers include his famous "We Shall Fight on the Beaches" speech delivered in 1940 and an unpublished novel he wrote at age 23.

Churchill was Britain's wartime leader, serving from 1940 to 1945, then again from 1951 to 1955. He was a noted orator, as well as a writer and historian.

His descendants bought his huge archive, totalling 2,500 boxes, in 1995 with £12 million ($19.4 million) of lottery money and it has been housed at Cambridge University.

Now the Churchill Archive Trust has struck a deal with Bloomsbury to publish Churchill's letters, telegrams, manuscripts and photographs in 2012.

The documents range from political papers and speeches to correspondence with people such as suffragette Sylvia Pankhurst and personal items such as his school reports and personal bets with friends and political colleagues.

FDR archive to 'help fill gaps' in record

Roosevelt became president in 1932 in the depths of the Great Depression, launched the New Deal that was credited with easing the economic crisis and led the U.S. through the war years, dying in office in 1945.

Roosevelt's personal secretary Grace Tully and another personal secretary Marguerite (Missy) LeHand kept his archive after his death. It is expected to expose both his personal life and connections with other famous people of the time, including Joseph Kennedy.

U.S. Archivist David Ferriero said the archive will "help fill gaps in the record of a presidency that changed America.

"Roosevelt did not keep a diary, did not sit for extensive interviews with historians, did not live to write his memoirs, and he never completely confided in anyone, not even his wife," Ferriero said.

FDR's archive has been in limbo after being bought in 2001 by the Sun-Times Media Group, formerly Hollinger International, for $8 million US.

Hollinger put the items up for auction in 2004, but was forced to withdraw them after the U.S. National Archive claimed the presidential materials should belong to the public. The company agreed to donate them for a tax credit, until Sun-Times Media went bankrupt.

Instead Congress passed a bill that made the donation official as of June 30. The Roosevelt library, near Poughkeepsie, N.Y., took over handling the documents.