Son of the Hasmonean prince Simon, whom he accompanied on his last journey, together with his brother Judah and his mother. Simon, with his sons, was invited by his son-in-law Ptolemy to a banquet in the fortress of Docus, near Jericho, where he was murdered, his sons being first put in fetters and then killed. The accounts in I Maccabees and in Josephus do not agree as to whether Mattathias was slain at the same time as his father, or later; Josephus, however, probably reports the affair more correctly, as he refers also to other sources.