Having neglected matrimony in favour of his career, William married Agnes when he was at the relatively late age of 42, and she was 20 years his junior.
The co-heiress of Hertfordshire knight Sir Sir Edmund Berry, she brought more to the marriage than merely financial gain. Whilst William was away attending to his legal duties, Agnes was in charge of the estates in Norfolk, acting as a more than capable deputy, ably dealing with the demands placed upon her, as well as providing William with several children.
Despite the advantageous nature of the marriage, it appears to have also been a happy one, judging from their correspondence. Following William’s death in 1444, Agnes remained as the matriarch of her tribe as they continued their upward rise.