character of many of the instruments wherewith he had to achieve his purposes, and also the fact that he had neither a great army at his back with which to enforce the fulfilment of treaty obligations—­for Florence never was a city of soldiers—­nor had he the prestige of an official position to lend weight to his words.  To all intents and purposes he was a private citizen of the Florentine republic.  Yet such was the dynamic power of the man’s marvellous personality, and the reputation he had earned, even in his early years, for supreme prescience and far-reaching diplomatic subtlety, that far and wide he was regarded as the greatest force in Italian politics.  Sixtus sallied forth to crush; he returned to the Vatican a crushed and a discredited man, to die of sheer chagrin over his defeat by Lorenzo in his designs upon Ferrara.

Then followed the memorable dispute, in 1472-1473, over the bishopric of Pisa, when the Pope’s nominee, Francesco Salviati, was refused possession of his see, Pisa being one of the Tuscan towns under the control of Florence.  To this Sixtus retaliated by seeking the friendship of Ferrante of Naples, a move Lorenzo anticipated by forming the league between Florence, Milan, and Venice.  This league thoroughly alarmed both the Pope and Ferrante, and on the latter visiting Rome in 1475 a papal-Neapolitan alliance was formed.

Even then hostilities might not have broken out had the young Duke of Milan not been assassinated in 1476, leaving an infant heir.  This entailed a long minority, with all its dangers, and the apprehensions regarding these were not fanciful, inasmuch as Lodovico Sforza, uncle of the baby Duke, usurped the position under pretext of acting as regent.  These crimes were plainly responsible for the Pazzi conspiracy in 1478 against the Medici themselves, a conspiracy which resulted in Giuliano, the younger brother of Lorenzo, being murdered in the cathedral, during mass, on the Sunday before Ascension, while Lorenzo himself was slightly wounded.  That Sixtus and his nephew were accessories before the fact is now regarded as unquestionable.  The vengeance taken by the enraged Florentines on the conspirators, their relatives, friends, and property, was terrible; the innocent, alas! being sacrificed indiscriminately with the guilty.

The Archbishop of Pisa, Francesco Salviati, had entered eagerly into the scheme, and, although his sacred office prevented him from actually assisting in the deed, he was present in the cathedral until the signal was given for the perpetration of the deed, when he left the building to secure the Palazzo Publico.  He was therefore summarily hanged with the others from the windows of the civic buildings.  Sixtus made the execution, or the “murder” as he called it, of Salviati, his pretext for calling on his allies to make war on Florence.  When he saw, however, that this action was only throwing the city more completely than ever into the arms of the