The attacks of the Maratha Empire on Goa during the mid-16th century precipitated the third major wave of migrations. In 1664 Shivaji, the founder of the Maratha empire, attacked Kudal, a town north of Goa, and began his campaign for Goa. After Shivaji's death on 3 April 1680, his son Sambhaji ascended to the throne. The onslaught of Sambahji along the northern territories of Goa drove nearly all the Christians from their homelands, and most of them migrated to South Canara. Migration increased with the fall of the Portuguese "Province of the North" (which included Bassein, Chaul and Salsette) and a direct threat to the very existence of Goa in 1738–40.