The official split took place in 1562, when two separate churches were officially established: the mainstream Calvinist and the smaller, more reformist, Polish Brethren or Arians.
Ametlik eraldumine leidis aset aastal 1562, kui rajati ametlikult kaks eraldi kirikut: peavoolu kalvinistid ja väiksem, reformistlikum poola vennad või ariaanid.