Following the Delhi Massacre, public figures across India (as well as most remaining British industrialists, civil servants, veterans, etc.) came to agree that the Indian people could no longer be subject to European colonialism. Mahatma Gandhi presided over a vote by the Indian National Congress in which they decided to declare war on the German Empire. The Russian Bolsheviks were a major supporter of Gandhi's INC, sending a number of military advisors and weapons through Central Asia. The United States of America also sent an enormous number of arms and munitions to support the INC, as well as providing low-interest loans. Over almost four years of bloody struggle, Indian troops managed to beat back the Deutsches Heer and Kaiserliche Marine, which were themselves terribly supplied thanks to a revolution back home, culminating in the Battle of Mumbai.
On June 19th of 1923 a representative of Kaiser Willhelm II and Mahatma Gandhi agreed to sign the Treaty of Calcutta, ending the Indian War of Independence, and recognising the legitimacy of the new Federation of Indian Princedoms and States. However, this new state's capacity to govern itself was limited, resulting in the Indian Warlord Era.