You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Josip_Broz_Tito

Context:
Josip Broz was born to a Croat father and Slovene mother in the village of Kumrovec, Croatia. Drafted into military service, he distinguished himself, becoming the youngest Sergeant Major in the Austro-Hungarian Army of that time. After being seriously wounded and captured by the Imperial Russians during World War I, Josip was sent to a work camp in the Ural Mountains. He participated in the October Revolution, and later joined a Red Guard unit in Omsk. Upon his return home, Broz found himself in the newly established Kingdom of Yugoslavia, where he joined the Communist Party of Yugoslavia (KPJ).

Question:
What ethnicity was Tito's father?

Croat