His enthusiastic championship of the liberty of the Greeks attracted the attention of the Government, which appointed him censor of the public press.
His refusal of this appointment won him great popularity and the lifelong friendship of Charles Forbes René de Montalembert.
After contact with the Pre-Raphaelites of England, where he lived for three years and married, and especially of Montalembert's encouragement, he visited again, in company with his wife, all the important galleries of Europe, although he had meanwhile become lame and had to drag himself through the museums on crutches.
Prominent men like Gladstone, Manzoni, and Thiers became interested in his studies, which he published in four volumes under the title "L'art chrétien" (1861-7).
Rio describes the more notable incidents of his life in the two works, Histoire d'un collège Breton sous l'Empire, la petite chouannerie (1842) and Epilogue à l'art chrétien (2 vols., 1872).