This book delves into the historical significance of Ghadir-e-Khum, an event where Prophet Muhammad (s.a.w.w.) gathered thousands of Muslims during his return from the farewell pilgrimage and declared Imam Ali (A.S.) as the Mawla (leader) of all believers. The declaration, "For whoever I am his leader (Mawla), Ali is his leader (Mawla)," holds profound importance in Islamic belief, particularly in Shia tradition. This book explores the context, narration, and interpretations of the event and its implications on the future of the Muslim ummah. The event of Ghadir-e-Khum is seen as the moment where the religion of Islam was completed, as confirmed by the revelation of the verse in the Quran: "Today I have perfected your religion for you and completed My favor upon you and have approved Islam as your religion" (Quran 5:3). The book also examines how the event shaped the concept of leadership (Wilayat) and authority in Islam.