 It is estimated that 88% of them died during the first ten years of colonial rule owing to a combination of disease and war.Likewise, in Tabasco the population of approximately 30,000 was reduced by an estimated 90%, with measles, smallpox, catarrhs, dysentery and fevers being the main culprits.The Spanish engaged in a strategy of concentrating native populations in newly founded colonial towns, or "reducciones" (also known as "congregaciones").