The expansion of diplomatic activity abroad can be seen in the increase of the official representation of foreign states in different European capitals during the seventeenth century. Spain created an important diplomatic network of agents throughout the Continent to guarantee the maintenance of peace. Bedmar, Gondomar, Zuniga, Cardenas, Aytona, Osuna and Guevara were all remarkable diplomats during this period. They were helped by a group of active diplomats from Flanders, among them Jacques Bruneau, Gabriel de Roy, Jean de Croy, the baron of Auchy, Pedro Pablo Rubens, and Van Male. France consolidated its diplomacy under Richelieu, as is proved by the large number of French ambassadors during this period. In the same way, the English crown was officially represented in most European countries during the reign of James I.

The peace treaties of Vervins (1598), London (1604), and the truce of Antwerp (1609), which established the era known as Pax Hispánica, marked the new pulse in international relations. The Spanish monarchy, thanks to its skilful manoeuvres and network of diplomats, had managed to make all of these agreements profitable. We should not interpret these years as simply those of a monarchy financially exhausted and politically conformist, accepting a secondary international role played in a Europe overcome by permanent changes. As can be demonstrated by analysing the period 1620–50, the years of truce and peace made it possible for Spain to reorganize finances and recover the military impetus lost during the long years of conflict. Philip IV's monarchy would once again be able to dispatch its many, multi-national armies to the battlefronts with the aim of recovering lost positions and prestige on the international scene.

The treaty of London and the mutual convenience of peace

The accession to the English throne in July 1603 of the Scottish king, James VI and I, ushered in a new era. Not only was his attitude toward Catholics more tolerant, but he was influenced by those, such as his secretary Sir Robert Cecil, first earl of Salisbury, who advocated a lasting peace agreement. In addition, with Sir Walter Raleigh accused of participating in a plot to dethrone James I, Raleigh's party had disappeared from the political scene. All these factors channelled events in a new direction.