This is historical analysis of a peculiar festival in the South Indian Kerala alone which is celebrated by both the Christians and the Hindus alike.  This is the festival of Onam which is connected with the Asura King Mahabali (The Great Sacrifice) and the Sura Lord of Heaven.  There is also a long forgotten historical period of over six decades denoted by the Kalabhra Inter-regnum. Along with that is the myth of the Prestor John falling in the same period of time. This is an attempt to connect them all to explain what happenned