events such as jousting, with the two kings competing, though not against each other. With France and Spain vying for England's allegiance, Wolsey could choose the ally that better suited his policies. Wolsey chose Charles mainly because England's economy would suffer from the loss of the lucrative cloth trade industry between England and the Netherlands had France been chosen instead. Under Wolsey's guidance, Europe's chief nations sought to outlaw war among Christian nations. Garrett Mattingly, who has studied the causes of wars in that era, found that treaties of non-aggression such as this one could never be stronger than their sponsors' armies. When those forces were about equal, the treaties typically widened the conflict. That is, diplomacy could sometimes postpone war, but could not prevent wars based on irreconcilable interests and ambitions. What was lacking, Mattingly concludes, was a neutral power whose judgements were generally accepted either by impartial justice or by overwhelming force. Alliance with Spain The Treaty of London is often regarded as Wolsey's finest moment, but it was abandoned within a year. Wolsey developed links with Charles in 1520 at the Field of the Cloth of Gold. At the Calais Conference Wolsey signed the Secret Treaty of Bruges (1521) with Charles V, stating that England would join Spain in a war against France if France refused to sign the peace treaty and ignored the Anglo-French treaty of 1518. Wolsey's relationship with Rome was also ambivalent. Despite his links to the papacy, Wolsey was strictly Henry's servant. Though the Treaty of London was an elaboration on Pope Leo's ambitions for European peace, it was seen in Rome as a vain attempt by England to assert her influence over Europe and steal some papal thunder. Furthermore, Wolsey's peace initiatives prevented a crusade to the Holy Land, which was the catalyst for the Pope's desire for European peace. Cardinal Lorenzo Campeggio, who represented the Pope at the Treaty of London, was kept waiting for many months in Calais before being allowed to cross the Channel and join the festivities in London in what may have been a display by Wolsey of his independence of Rome. An alternative hypothesis is that Campeggio was kept waiting until Wolsey received his legacy, thus asserting Wolsey's attachment to Rome. Though the English gain from the wars of 1522–23 was minimal, their contribution certainly aided Charles V in his defeat of the French, particularly in