In 1885–6 the Mostyn family commissioned a painting from the artist Herbert Sydney which depicted them in the guise of their late fifteenth-century ancestors. Loaded with references to the family's heritage and their embeddedness in Welsh history, the artwork was designed to recreate a prominent family tradition centred on Henry Tudor's victory at Bosworth in 1485. This article traces the invention and development of the tradition in the nineteenth century and assesses how and why the family fashioned the legend into a central part of their public image. The case study opens up wider questions about the Welsh gentry's engagement with the history and culture of Wales, suggesting a level of ancestral patriotism which complicates the prevalent narrative of 'anglicization'.