The claims came in stages. In the early 1880s Mirza Ghulam Ahmad presented himself as a mujaddid, a renewer sent at the head of a century, which is a familiar and uncontroversial category in Islamic thought. By 1891 he was announcing that he was the Promised Messiah and the Mahdi, and also the awaited figure of other traditions under their own descriptions.
Two positions attached to that. First, he taught that Jesus did not die on the cross but survived, travelled east, and died a natural death, which removed the expectation of a bodily return and allowed a messiah to come in likeness rather than in person. Second, he held that armed jihad was not appropriate to his age, that the defence of Islam belonged to argument and to writing, and that this followed from the messiah's function rather than from any abrogation of the law.
The hardest question is prophethood. The overwhelming majority position in Islam is that Muhammad is the seal of the prophets and that no prophet follows him, and Ghulam Ahmad used prophetic vocabulary of himself while insisting the sense was derivative, a reflection of Muhammad's prophethood rather than an independent one bringing new law.
How strictly to read that qualification split his own community within six years of his death. The Qadian branch, organised under a caliphate, understands him as a prophet in the subordinate sense; the Lahore branch, formed in 1914, holds that he was a renewer and not a prophet at all, and that reading him otherwise put the movement outside the consensus unnecessarily. Both branches continue.