Within twenty years of Charles VIII's invasion, Italians had begun to speak regretfully of the happy days which preceded the coming of the French. They looked back on the years before 1494 as an age of peace and prosperity, when endless opportunities were open to men of talent, and when life in court and city was marked by a round of novel and refined pleasures. Their view of the past was nostalgic, yet the second half of the fifteenth century may rightly be considered the heyday of Italian civilisation. During the forty years which lay between the Peace of Lodi (1454) and the French invasion, the rulers of Italy had done much to establish peace and order within their dominions and friendly relations with their neighbours. Quarrels between the various states were of less significance than the common interests which united them. Petty wars did not place serious hindrances in the way of the pursuit of wealth or the cultivation of the arts. Although the challenge to Italy's commercial supremacy was already formidable, the merchants had money to spend on pictures, books and building, whilst the princes used their earnings as mercenary captains to make their capitals centres of the art and learning of the Renaissance. The individual contribution to civilisation made by each state at a time when it was still independent and at peace bore fruit in the splendours of the early sixteenth century. A reverse side of the picture is the growing interest shown by foreign Powers in Italian affairs.