After the Peasants’ Revolt the Mowbrays’ plans for their estates were straightforward. They sought to maximise income from their lands and maintain the value of their assets, despite the period 1380–1530 being one of general agricultural depression. The period 1440–80 was particularly difficult for them.

The Mowbrays strove to maintain a ducal lifestyle and support expensive military campaigns, but it became increasingly difficult for them to live within their means. Referencing twenty-nine Mowbray manors, 1447–48 and 1472–73, Moye demonstrates that just twelve increased their income, although in some cases this was only by a very small amount. The seventeen manors from which income reduced included four medium to large manors. The reduction, however, was less than £1 in these manors, and there is no clear evidence of a direct link between manor size and loss of income. Three of the four Norfolk manors showed losses, as did five of the six manors in Suffolk. Location, or a different management style, may have been important factors, as seven of the thirteen manors in Sussex showed increases in income.

John Mowbray, the third Duke of Norfolk, suffered from an incompetent and unscrupulous receiver general in the 1440s, and the role of receiver general was subsequently abolished. However, by 1461 the family was heavily in debt despite the third and fourth dukes struggling to economise by occasionally suspending the payment of wages, fees and annuities to members of staff as well as other measures.

The incomes of the dukes of Norfolk suffered because they were required to support three dowagers: Elizabeth Fitzalan, wife of Thomas Mowbray, who lived until 1425; Constance Holland, who held Mowbray lands until 1437; and Katherine Neville, who received about one third of the Mowbray estates as her dower after the death of her first husband, John Mowbray, in 1432. When John Mowbray, the fourth Duke of Norfolk, died in 1476 the Mowbray dukedom came to an end, and he left another dowager, Elizabeth Talbot, daughter of the Earl of Shrewsbury.

The manor court proceedings and the bailiffs’ accounts were important parts of the Mowbray administrative machine and enabled the lord, through the steward and other council members, to find ways of protecting their income and maintaining the value of their assets.