Casolani took his surname from Casole, the little town from which his family removed to Siena. In the ducal gallery of Florence there is a portrait of a lady with three men, in the same piece, which is said to represent Lucrezia Piccolomini, with her three sons, Alessandro Casolani, Francesco Vanni, and Ventura Salimbeni, whom she bore to different husbands, in the course of a few years. This makes Alessandro the stepson of Arcangiolo Salimbeni, and the uterine brother of Ventura and of Vanni. I cannot find this story in any author, except in Niccolò Pio, a Roman writer of no authority, whose manuscript, containing notices of two hundred and fifty artists, which was drawn up about 1724, is preserved in the Vatican library.[301] The old writers of Siena have taken no notice of so remarkable an event, and we cannot, therefore, give credit to Pio, a stranger, and a modern author. The relation then in which Alessandro stands to Arcangiolo is that of scholar; but he learnt more from Cav. Roncalli in Siena and in Rome. He remained long in the latter city: he designed the finest works it contained, and obtained some idea of different styles. This knowledge was increased by a journey which he made some years afterwards to Pavia, where he painted in the Carthusian monastery, and in other places. His manner is prodigiously varied. It exhibits traces of the best style of Roncalli, a good design, sobriety of composition, a modesty of colouring, and tranquil harmony. He seems also to have aimed at originality, for he was continually altering his style, mingling it with the graces of various artists, and sometimes striking out into a novel path. He possessed promptness of genius and of execution: he was quick in committing his ideas to the canvas; and when dissatisfied with his work, he often chose to cancel the whole, rather than to correct a part. Although unacquainted with ideal beauty, he was esteemed by Guido, who may be considered as the father of modern painters, and who said of him "this truly is a painter." Whoever would see his best work, may examine the martyrdom of S. Bartholomew, at the Carmine of Siena. It is a picture of considerable size, with great variety in the figures and in the expression, and altogether excites surprise. We are told that when Roncalli examined it, he at length exclaimed, that the art of that period was comprised in that picture. But the short life of Casolani prevented him attaining the excellence which this specimen promised. His works are in various cities of Tuscany, and also in Naples, Genoa, and Fermo, in the metropolitan church of which there is a picture of S. Louis of France, that is numbered among the choice paintings in that city.