 His father , Sir Oswald Mosley was a Labour minister , and a Member of Parliament for both the Conservative and Labour parties in the 1920s . By the 1930s , he had left mainstream politics and become the leader of the British Union of Fascists ( BUF ) . His first wife died in 1933 , and in 1936 Sir Oswald married Diana Mitford , in a ceremony in Germany attended by Joseph Goebbels and Adolf Hitler . Max was born in London in April 1940 during the early days of the Second World War to Diana and Oswald . In May , Sir Oswald , who had campaigned for a negotiated peace with Nazi Germany , was interned by the British Authorities under Defence Regulation <unk> , along with most other active fascists in Britain . Lady Mosley was imprisoned a month later . Max and his brother Alexander were not included in this internship and as a result were separated from their parents for the first few years of their lives . In December 1940 , then @-@ prime minister Winston Churchill , asked Home Secretary Herbert Morrison to ensure Lady Mosley was able to see Max regularly . 
