Ptolemy XI Alexander II in Wikipedia

Ptolemy XI Alexander II (Πτολεμαῖος Ἀλέξανδρος, Ptolemaĩos Aléxandros) was a member of the Ptolemaic dynasty who ruled Egypt for a few days in 80 BC. Ptolemy XI was born to Ptolemy X Alexander and either Cleopatra Selene or Berenice III. Ptolemy IX Lathryos died in 81 BC or 80 BC, leaving no legitimate heir, and so Cleopatra Berenice (another name of Berenice III) ruled alone for a time. However, Rome's Sulla wanted a pro-Roman ruler on the throne, and sent the young son of Ptolemy X to Egypt, displaying Ptolemy Alexander's will in Rome as justification for this obvious intervention. The will also required Ptolemy XI to marry Cleopatra Berenice, who was his stepmother and half-sister (or possibly his natural mother - the ancient sources are unclear). However, nineteen days after the marriage, Ptolemy murdered his bride for unknown reasons, an unwise move since Berenice was very popular; Ptolemy was immediately lynched by the citizens of Alexandria. He was succeeded by Ptolemy XII.