Complex sentence: His father, William Boden, was born in Ballinasloe on the border of counties Galway and Roscommon, but went in his youth to join his uncle in the latter's evidently prosperous drapery story in Magherafelt, Co. Derry.
Split into simpler sentences: His father, William Boden, was born in Ballinasloe on the border of counties Galway and Roscommon. In Williams youth, he went to join his uncle in the latter's evidently prosperous drapery story in Magherafelt, Co. Derry.