Complex sentence: His paternal grandfather James Woodward was an ironmonger's haulier from Gloucestershire who married a woman from Wiltshire, and his maternal grandfather married Ada Jones from Pontypridd, whose parents came from Somerset and Wiltshire.
Split into simpler sentences: His paternal grandfather, James Woodward, was an ironmonger's haulier from Gloucestershire, who married a woman from Wiltshire. His maternal grandfather was Welsh, and his maternal grandmother, Ada Jones, was born in Pontypridd, to parents came from Somerset and Wiltshire.