Ahmadiyyah is a missionary-oriented sect of Indian origin, founded in Qadiyan by Miraz Ghulam Ahmad (1839-1908). The sect believes its founder to be the madhi, the Christian Messiah, an avatar of the Hindu god Krishna, and a reappearance of Muhammad. The sect believes that Jesus did not die in Jerusalem but feigned death and resurrection, and escaped to India where he died at the age of 120.
Although Ahmadiyyah departs from mainstream Sunni Islamic doctrines in terms of its belief in the special status of Mirza Ghulam Ahmad, they follow most of the main duties of Islam such as prayer, fasting, pilgrimage and almsgiving, as well as the basic Sunni interpretations of Islamic theology. Of the two branches of Ahmadiyyah in existence today, the minority Lahore branch, is considered to be within mainstream Sunni theology. The majority Qadiyanis are, however, not considered to be part of Islam by orthodox Muslims.
http://philtar.ucsm.ac.uk/encyclopedia/islam/sunni/ahmad.html