John Parricida ("killer of relatives"; born 1290, died December 13, 1312 or 1313, probably in Pisa) was a son of Duke Rudolph II of Austria from the Habsburg family. As his father had had to waive his right to the fiefs of Austria and Styria in the Treaty of Rheinfelden of 1283, he felt deprived of his inheritance. In 1308, he assassinated his uncle Emperor Albert I and fled to Italy. It is suspected that he became a monk in Pisa.