Background
Salaj was born in Valpovo and received secondary education as a tailor.
Salaj was born in Valpovo and received secondary education as a tailor.
In 1907 he travelled to Austria, Germany and Switzerland looking for work, and became a social democrat and a trade union activist. In 1909 he moved to Sarajevo and became a local sewing trade union representative. After World War I he moved to Slavonski Brod where he became further involved in politics, and led the local branch of the Social Democratic Party to become the Communist Party.
Between 1930 and 1944 he was the Communist Party of Yugoslavia representative with the Communist International, stationed in the Soviet Union.
His remains are buried in the Tomb of the People"s Heroes, Zagreb.