Joseph Tiso was a Slovak politician who lived from 1887 to 1947. He became the first president of Slovakia in 1939, when the country was separated from Czechoslovakia and became a puppet state of Nazi Germany.
Tiso was a Catholic priest before he entered politics, and he used his religious influence to support Slovak nationalism. He believed that Slovakia should have its own independent state, separate from Czechoslovakia.
During World War II, Tiso cooperated with the Nazis and allowed them to deport Slovak Jews to concentration camps. He also supported the Slovak state's participation in the war on the side of Nazi Germany.