Peregrine Bertie, 13th Baron Willoughby de Eresby

Peregrine Bertie, 13th Baron Willoughby de Eresby was the son of Katherine Willoughby, 12th Baroness Willoughby de Eresby, and Richard Bertie. Richard Bertie was Lady Willoughby de Eresby's second husband, the first being Charles Brandon, Duke of Suffolk. Peregrine Bertie's half-brothers, Henry and Charles Brandon, died as teenagers four years before his birth. His sister Susan married the Earl of Kent and then the nephew of Bess of Hardwick. Owing to religious politics, his parents had to move outside England and the boy was born at Wesel on the River Rhine. His first marriage was to Mary de Vere, daughter of John de Vere, 16th Earl of Oxford.