Complex sentence: William was probably born in 1409 or 1410, second son of Eudo de Welles and Maud de Greystoke; his paternal grandfather was John de Welles, 5th Baron Welles.
Split into simpler sentences: William was probably born in 1409 or 1410, second son of Eudo de Welles and Maud de Greystoke. His paternal grandfather was John de Welles, 5th Baron Welles.