The contest ran from 1906 to 1938 , interrupted by World War I and in 1931 .
The contest was suspended in 1939 when the hosts , Poland , were invaded at the start of World War II .
The contest ran from 1906 to 1938 , interrupted by World War I and in 1931 , but was suspended in 1939 when the hosts , Poland , were invaded at the start of World War II .