This Day in Ancient History: ante diem vi kalendas apriles

538 B.C. — Accession of Cyrus the Great to the Persian throne (according to one reckoning)*

196 B.C.– Ptolemy V Epiphanes becomes pharaoh of Egypt (accordingto one reckoning)*

47 B.C. — Gaius Julius Caesar is victorious in Alexandria

47 B.C. — Ptolemy XIII drowns while trying to cross the Nile (related to the foregoing event?)