Who did Cleopatra hire to kill her brother ptolemy?

Cleopatra hired the Roman general and ally, Julius Caesar, to help her eliminate her brother Ptolemy XIII, who was co-ruler with her. While she did not directly order his assassination, the political maneuvering and military support from Caesar ultimately led to Ptolemy's defeat and death during the conflict over the throne. This alliance with Caesar was pivotal in consolidating Cleopatra's power in Egypt.