Some discrepancies in the accounts of these transactions and the dates of them in the contemporary historians have led Burriel into supposing that the Cardinal Riario made two journeys to Milan, the first in 1472, and the second in 1473, and that on both occasions he arrived there on the 12th of September. The first journey however is, as far as I can find from a careful examination of the authorities, wholly imaginary. The difficulty seems to have been, that Corio represents Girolamo Riario, the proposed bridegroom, to have been invested with the County of Imola on the 6th of November, 1472. And it is difficult to suppose that this could have been done before all the conditions of the marriage were finally arranged, which they certainly were not till after the Cardinal's journey to Milan. But Corio is a very untrustworthy guide as far as dates are concerned. Another blunder of his in the very passage, in which he tells of Imola having been given to Girolamo Riario as Catherine's dower, might have put Burriel on his guard. When the marriage was determined on, he says, the Duke "gave her Imola for her dower.... After that—_dipoi_—on the 20th of August, Borso of Este, Marquis of Ferrara, died." Now that prince died on the 27th of May, 1471. Muratori (ad ann. 1473), quoting Platina assigns the true date of 1473 to Girolamo's investiture of the County of Imola; but supposed that that principality was purchased by the Cardinal of the Manfredi family for forty thousand ducats, and given by him to his brother. But as to this point of the story Burriel must be considered to be correct. For he says, that the conditions of the marriage, including the giving Imola as the bride's dower, "are proved by Catherine's last Will and Testament, which we have before us, and by Filippo of Bergamo in his life of the Count, and by Andrea Bernardi in his chronicle, both of whom were contemporary writers." The notion of the sum of forty thousand ducats having been paid by the Riarios for Imola seems to have arisen from the fact, that that sum was by the marriage contract stipulated to be paid down by the Pope.[215] It is remarkable that the two most notable historians of Milan in recent times, Verri and Rosmini, are both wholly silent as to the marriage of Catherine, the negociations with the Cardinal Riario on that subject, and the acquisition of Imola. Count Pietro Verri died in 1797, leaving his History of Milan incomplete. It has been often reprinted, and has been always highly esteemed by his fellow countrymen. The four bulky and handsome 4to. volumes of the Cavaliere Carlo de' Rosmini on the History of Milan were printed in 1820; and have taken the rank of a standard work.