 From 1651 to 1756, the Mbayá were a severe threat to the Spanish in Paraguay, the eastern and southern bands making an uneasy peace with the Spanish in the latter year.The first moderately successful Roman Catholic mission among the Mbayá was established in 1760 east of the city of Concepción, Paraguay, thus beginning a process of absorbing them into the population of Paraguay.However, the Mbayá were never politically united.