Supporting both the Bucks Militia and the Bucks Yeomanry, the family became increasingly involved in military matters.

The eldest son, Richard, shared his father's involvement in military and political affairs. In 1822 he was granted a dukedom for his rather lacklustre efforts in government, the only one granted by William IV.

He became the 1st Duke of Buckingham and Chandos - Chandos was the family name of his heiress wife, Anna Eliza. She brought with her a great art collection, which her husband improved on by buying from the auctions driven by the French Revolution. The Duke was a spendthrift, who shut up his home for two years to economise, only to sail around the Mediterranean buying crateloads of antiquities. Nevertheless, he managed to buy the long-sought Lamport estate in 1826, enlarging the garden and having it remodelled by head gardener James Brown.

Work was still being undertaken as the funds began to dry up, including turning the Menagerie into a museum, repairing the Temple of Venus and establishing a new deer park to the southwest of the garden. Parties were rare but extravagant and grand, such as the famous party, the "Stowe Junket" for the baptism of the 1st Duke's grandson, reputedly the largest ever.