However, his interest in arts led quickly him to study in the studios of sculptors Bertel Thorvaldsen and Pietro Tenerani, the painter Tommasso Minardi and the goldsmith Fortunato Pio Castellani.
[3] He published relevant works, such as La Materia nella Divina Commedia and Carteggio Dantesco and designed a series of topographic maps to be used by students of the Divine Comedy.
His house was the meeting place of national and international scholars, such as François-René de Chateaubriand, Stendhal, Henry Wadsworth Longfellow, Franz Liszt, Honoré de Balzac, Renan, Hippolyte Taine, Frédéric Ozanam, Jean-Jacques Ampère, George Ticknor, Ferdinand Gregorovius, Alfred von Reumont, Démosthène Ollivier.
Their son, Onorato, was Minister of Foreign Affairs of the Kingdom of Italy, while their daughter Ersilia was an archaeologist and the first woman who was admitted to the oldest scientific academy, the Accademia Nazionale dei Lincei.
A street in Rome is named after Michelangelo Caetani, which is located to the south of Via delle Botteghe Oscure in rione XI (Sant'Angelo).