In which year of the Hijra was Hajj made obligatory?

Scholars differ on the exact year Hajj was mandated, but the correct view is that it was obligated in the ninth year of the Hijra. This is because obstacles, such as the prevention by Quraysh, had been removed, and Makkah had been purified from disbelief after its conquest. This aligns with the Hajj verse in Surat Aal 'Imran, which was revealed in the year of delegations. As for the Prophet's (peace and blessings be upon him) not performing Hajj in the ninth year, it was due to two reasons: the large number of delegations coming to him in the Year of Delegations, and his desire to purify Hajj for the Muslims, as he announced in that year the prohibition of polytheists from performing Hajj and of circumambulating naked.