Before this event, he had sent his son, the king of Antioch, into Tuscany with sixteen hundred German cavalry, to secure Florence to his party; where, since the death of Buondelmonte, the Guelfs and Ghibellines, always in opposition, had not ceased fighting. There was seldom an assembly, a festival, a public ceremony, without some offence given, either by one or other of the parties. Both flew to arms; chains were thrown across the streets; barricades were immediately formed, and in every quarter, round every noble family; the more contiguous, who had the most frequent causes of quarrel, fought at the same time in ten different places. Nevertheless the republic was supposed to lean towards the Guelf party; and the Florentine Ghibellines, in their relations with other people, had never sought to separate from their fellow-countrymen, or to place themselves in opposition to their magistrates. Frederick, fearing to lose Florence, wrote to the Uberti, the chiefs of the Ghibelline faction, to assemble secretly in their palace all their party, to attack afterwards in concert and at once all the posts of the Guelfs; whilst his son, the king of Antioch, should present himself at the gates, and thus expel their adversaries from the city. This plan was executed on the night of Candlemas, 1248; the barricades of the Guelfs were forced in every quarter, because they defended themselves in small bands against the whole of the opposite party. The Ghibellines, masters of the town, ordered all the Guelfs to quit it. They afterwards demolished thirty-six palaces belonging to the same number of the most illustrious families of that party; and intimidating the other cities of Tuscany, they constrained them to follow their example, and declare for the emperor.