What happened to Cleopatra's two brothers?

Cleopatra's two brothers were trying to throw cleopatra off her birth right, the throne. So, in anger, Cleopatra poisned one of her brothers and drowned the others. Though many people think that one of Cleopatra's brothers drowned at war, they are wrong. I have read many biographys about Cleopatra and i have reserached from websites that end in .gov or .edu . i trust these websites and National Geographic where i found this information. Your question was a well thought out question and i hoped i answerd it for you.