Julian was the son of Sullivan, leader of the human community in the city of Mak. Like others of his generation, Julian was born mute. Sullivan never revealed who Julian's father was, although many speculated. At his birth, Julian was taken by Sullivan's chimp adoptive sister Alaya, who raised him for the first decade of his life. After that, Julian was kidnapped by Wyn and taken back to Sullivan, whom he greatly resented. Only after Sullivan and Alaya had reconciled in the face of a greater danger did Julian come to accept his natural mother. Julian was able to communicate through sign language, but also telepathically through Sister Martha. Alaya and Sullivan entrusted the care of Julian to Hulss and sent them out of Mak before the final battle which destroyed the entire city. Hulss and Julian made a home in the Empty Lands for many years, where Julian raised a family of his own.
- Julian is exclusive to the continuity of the Planet of the Apes comic books published by BOOM! Studios.
- Julian is exclusive to the continuity of the BOOM! Studios Planet of the Apes mythos.