Gat Chulian was the ruler of ancient Malolos (Li-Han), Bulacan. He belongs to the Royal clan that rules the Lakanate of Tondo (The Lakanate of Tondo stretches from Tondo to Bulacan and Pampanga. The rulers were chosen among the royal kinship and were given the title Gat in Bulacan). His descendants used his whole name composition Gatchulian with variations like Gatchalian as their surname.
Reference:
- Olmos, Arturo T., Tiongson Ancestry (1600 A.D. - 2000 A.D.)