The Kalinga are one of several large, historically non-Christian groups living in the mountains of northern Luzon. They are grouped together on the grounds of cultural and linguistic similarity rather than common identity - according to Lawless (1993), 'Kalinga' was originally an exonym meaning "enemy". The principal source on this culture (Dozier, 1966) focuses on the Northern Kalinga, who were less acculturated than the Southern Kalinga at this time.