The intermedio (also intromessa, introdutto, tramessa, tramezzo, intermezzo, intermedii), in the Italian Renaissance, was a theatrical performance or spectacle with music and often dance, which was performed between the acts of a play to celebrate special occasions in Italian courts. It was one of the important predecessors to opera, and an influence on other forms like the English court masque. Weddings in ruling families and similar state occasions were the usual occasion for the most lavish intermedi, in cities such as Florence and Ferrara. Some of the best documentation of intermedi comes from weddings of the House of Medici, in particular the 1589 Medici wedding (between Christina of Lorraine and Ferdinando I de' Medici, Grand Duke of Tuscany), which featured what was undoubtedly both the most spectacular set of intermedi, and the best known, thanks to no fewer than 18 contemporary published festival books and sets of prints that were financed by the Grand Duke. Intermedi were written and performed from the late 15th century through the 17th century, although the peak of development of the genre was in the late 16th century. After 1600 the form merged with opera, for the most part, though intermedi continued to be used in non-musical plays in certain settings (for example in academies), and also continued to be performed between the acts of operas. Development The first intermedii were not in Florence but in Ferrara at the end of the 15th century between the five acts of plays by the classical authors Plautus and Terence. Writing of the "intermezzi" at the wedding of Lucrezia Borgia in 1502, Isabella d'Este said that they were more interesting than the boring commedia, "a remark destined to be often repeated". Ferrara intermezzi at this period were short and without a unifying theme; they included choruses, recitations and moresca dances. But by 1513 there was a unifying allegory, explained at the end. It was for Florentine public celebrations that Intermedii came into their own; several were organised by Machiavelli when he was part of the government of the Republic of Florence in the early 16th century, and the returning Medici adopted a policy of keeping the aristocracy occupied by involving them in productions. As the intermedio developed in the 16th century, it grew more and more elaborate, often becoming a "play within a play"; for example during a five-act play, an intermedio would consist of four parts, which