The Investiture of the Prince of Wales in 1969 was a crowning achivement for Lord Snowdon. Personally asked by HM The Queen to oversee the ceremony - as a Welshman, member of the Royal family and foremost a designer, he was an inspired choice, and was created Constable of Caernarvon Castle for the ceremony. The Investiture was a triumph, and when asked about his designs, Snowdon replied 'I am not a modernist for the sake of being modern. I just happen to be alive in 1969'.

Working with his great friend Carl Toms (who had been mentored by Oliver Messel), and John Pound, the brutalist designer from the Ministry of Works, the designs for the ceremony were ground-breaking and celebrated both modernity and antiquitity, in a time when Welsh independence and its place within the Union was at risk.

Snowdon's design for the now famous investiture chair was equally modern, manufactured at the Remploy factory in Bridgend. Taking the design of the Prince of Wales feather from a badge for the Cader Idris Volunteers, a badge Snowdon treasured on his desk for many years.