I stumbled across an Italian blog which I think our readers will find very interesting, called 
Scuola Ecclesia Mater. The author of it has created some very nice and very big collections of images on various themes; here are just a few from two of his recent posts, one on 
historical images of the Papal Corpus Christi procession, and another on 
Corpus Christi processions in general.
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| Giovanni Maria Morandi, Alexander VII Chigi in the Corpus Christ procession held on May 27, 1655, Musée des Beaux-Arts, Nancy | 
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| Ferdinando Cavalleri, Corpus Christi Procession with Pope Gregory XVI  in the Vatican. (This is the staircase which descends from the Sistine Chapel to St. Peter's Square) | 
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| Giovanni Bellini, Corpus Christi Procession in St Mark's Square, Venice. | 
 