Complex sentence: The witch trial was caused by the priest sira Jón Magnússon, who accused a father and son, Jón Jónsson the Elder and Jón Jónsson the Younger, for witch craft.
Split into simpler sentences: The witch trial was caused by the priest sira Jón Magnússon. He accused a father and son, Jón Jónsson the Elder and Jón Jónsson the Younger, for witch craft.