The first civil war broke out in 1384 CE four years before the death of aging Firoz Shah Tughlaq, while the second civil war started in 1394 CE six years after Firoz Shah was dead. These civil wars were primarily between different factions of Sunni Islam aristocracy, each seeking sovereignty and land to tax dhimmis and extract income from resident peasants. While the civil war was in progress, predominantly Hindu populations of Himalayan foothills of north India had rebelled, stopped paying Jizya and Kharaj taxes to Sultan's officials. Hindus of southern Doab region of India (now Etawah) joined the rebellion in 1390 CE. Tartar Khan installed a second Sultan, Nasir-al-din Nusrat Shah in Ferozabad, few kilometers from the first Sultan seat of power in late 1394. The two Sultans claimed to be rightful ruler of South Asia, each with a small army, controlled by a coterie of Muslim nobility. Battles occurred every month, duplicity and switching of sides by amirs became commonplace, and the civil war between the two Sultan factions continued through 1398, till the invasion by Timur.