Complex sentence: Beaumont was born in 1361 in the Duchy of Brabant, the only son of Henry Beaumont, 3rd Baron Beaumont (1340-1369) by his wife Margaret de Vere, daughter of John de Vere, 7th Earl of Oxford by his wife Maud de Badlesmere.
Split into simpler sentences: Beaumont was born in 1361 at the Duchy of Brabant to Henry Beaumont, 3rd Baron Beaumont and Margaret de Vere. His maternal grandparents were John de Vere, 7th Earl of Oxford and his wife Maud de Badlesmere.