Pierre Guillon de Prince believed to be first in France to formally apologise for ancestors’ allegiances to slavery Pierre Guillon de Prince believed to be first in France to formally apologise for ancestors’ allegiances to slavery An 86-year-old man has issued what is believed to be the first formal apology by someone in France for their family’s role in transatlantic slavery. Pierre Guillon de Prince’s ancestors, based in Nantes, which was the country’s largest port for transatlantic slavery,