Complex sentence: Owing to the harsh conditions, the Indians rose in arms against the transfer, and the so-called Guarani War ensued, a disaster for the Guarani, in which the Jesuits appeared, from the Portuguese perspective, to have had a hand.
Split into simpler sentences: Owing to the harsh conditions, the Guarani rose in arms against the transfer, and the so-called Guarani War ensued. It was a disaster for the Guarani, in which the Portuguese believed the Jesuits had a hand.