For the Riding-House, 'tis of so vast extent,
It does some mighty Temple represent,
Where seeing them ride, Admiring Indians wo'd
Adore each Horse there as a Semi-God.
In 1668, Mr Thomas Povey made a tour of the great houses of Derbyshire. He visited Chatsworth, Hardwick Hall, and then that ‘considerable Prince, the Duke of Newcastle, and his Pallace, Stables, Riding Houses, and Horses, which are more extraordinarie, then are to bee seene in Europe, If the Curiositie and Excellencie of their Manège Discipline, and Methods, bee considered'. The Duke of Newcastle was William Cavendish (1593-1676), well known for his interest in architecture, and renowned across Europe as an expert in the art of manège or horsemanship. His riding houses at Bolsover Castle and Welbeck Abbey survive, although the latter has been much altered (Figs 1,2 and 3). The first part of this article will examine their date, form and function, particularly through an assessment of the surviving fabric of the Riding House range at Bolsover, and will set them within the context of William Cavendish's other projects for buildings connected with horsemanship in Antwerp and London. The second part will go on to examine the social significance of William Cavendish's horsemanship and its importance for his political career. The tension between innovation and tradition that has been seen in William's Advice on politics and society, written for Charles II, can also be seen reflected in his practice of horsemanship. The concluding section, however, will argue that William Cavendish had personal reasons for wishing to be thought of on horseback, like Perseus upon Pegasus'.