Caesarion

On September 2, 44 BC, Queen Cleopatra VII of Egypt declared her son co-ruler as Ptolemy XV Caesarion, believed to be the son of Julius Caesar. An excerpt from the article:

"Ptolemy XV Caesar “Theos Philopator Philometor” (“the Father-loving Mother-loving God”) (c. 47-30 BCE), better known by his unofficial nickname Caesarion or “Little Caesar” in Greek, was the oldest son of Cleopatra VII (69-30 BCE) and was the last Ptolemaic king of Egypt. Caesarion is usually assumed to have been the son of Julius Caesar (100-44 BCE) who had an intermittent affair with Cleopatra from their meeting in 47 BCE until his death in 44 BCE.

Caesarion reigned as Cleopatra's co-ruler from 2 September 44 BCE to 12 August 30 BCE, when Cleopatra committed suicide. Although practically an exile, Caesarion was technically sole ruler of the Ptolemaic Kingdom until he was executed by Octavian (Caesar's grand-nephew, later Augustus Caesar, r. 27 BCE-14 CE) in late August 30 BCE."