Dr Guerry, of the School of History and Centre for Medieval and Early Modern Studies(MEMS), helps the EastEnders actor make the discovery during ‘Danny Dyer’s Right Royal Family‘, which airs at 9PM on 23 January on BBC One.

Dr Guerry, a medieval historian, explains to Dyer that his distant ancestor was extremely pious. He pierced the tongues of blasphemers, he prayed like a monk, and when he acquired the relic of the Crown of Thorns, purported to be worn by Jesus Christ at his crucifixion, he led a humble procession through the streets of Paris in honour of its arrival. As part of the programme, Danny Dyer restaged this sacred event by wearing only a linen tunic and walking barefoot through the French capital while carrying a replica of the relic (accompanied by a medieval choir). Dyer also pays a special visit with Dr Guerry to the Sainte-Chapelle, the Gothic chapel designed to contain the Crown relic.

For Dr Guerry, ‘it was an absolute delight to work with Danny Dyer and share my knowledge and intellectual passion for King Louis IX and the Sainte-Chapelle with him. I never imagined that I would meet a direct descendant of Louis (or that this person would be a famous actor) but I’ve enjoyed every minute of working on this project with the BBC.’

In her research, Dr Guerry examines the relationship between religious devotion and artistic representation in the Middle Ages. She is particularly interested in how the veneration of relics influenced Christian iconography in medieval Paris.