When we visited Florence a couple weeks ago we made a special point to visit the Bargello Museum to see Bernini's bust of Costanza. For that matter, we made a special point to visit as many Bernini sculptures as we could in our time there. The history of this piece is quite dramatic. Quoting Ingrid Rowland:
Bernini was not a nice man; he paid a thug to slash the face of his mistress Costanza after catching her in bed with his brother Luigi. [He also broke two of Luigi’s ribs with an iron rod] Before that incident, however, he had carved a portrait of Costanza, plump and tousled, looking as if she has just risen from bed; it is perfectly clear what both Bernini boys saw in her.
Our own desire to see Costanza was also thwarted - as the gallery she stood in was being restored. On our quest to see as many Bernini's as we could in Rome, this wasn't the only time we had a door shut. One morning after walking a long way across Rome to see a Bernini sculpture in a small church, the gate shut right in front of us for the afternoon hours. Another time (the Ufizzi) -the Bernini was in a room reserved only for special tours. For more information on Costanza and Bernini, you may refer to this new book:
Bernini's Beloved, by Sarah McPhee