Complex sentence: Foillan was the brother of Saints Ultan and Fursey: he is described as the'uterine brother' of Fursey, meaning that they had the same mother but not the same father.
Split into simpler sentences: Foillan was the brother of Saints Ultan and Fursey. He is described as the'uterine brother' of Fursey, meaning that they had the same mother but not the same father.