Cecil's foreign policy, like his home policy, showed the minister's desire for peace and moderation. Until the era of the Tudors, England had been a small and thinly populated land; it had been controlled commercially by foreign merchants ; and because it had held a position of only second rank as a kingdom, it had been dependent more or less on the friendship of the foreign powers. Henry VII and Henry VIII had begun the task of making England a power of first rank, and Elizabeth completed it. The old time enmity with France had been due, as far as the French were concerned, to the lands that English kings had had in France, and to the claims to the throne of France that these kings had set up. On England's part it had been due to the influence of France in Scotland, and to the danger that some French king might conquer the Netherlands, where lay the seat of English trade. Whoever in the past had controlled the cities of Flanders, whether the count of Flanders (to 1383), the duke of Burgundy (to 1477), or the emperors Maximilian and Charles V (to 1556), had been supported by England; and now that Philip II was lord of the Netherlands, it was inevitable that the traditional policy should be maintained, and that England should seek for an alliance with Spain. Such alliance was as necessary to Philip as to Elizabeth, for England could control the waterway from Spain and Portugal to the Flemish and German ports.
Cecil's policy was, therefore, to maintain under all circumstances friendly relations with Spain, and to this policy he adhered to the end of his career. Furthermore, he tried to play off one foreign power against another, and to prevent by every means possible the isolation of England and the combination of Spain and France against her. In general he was successful. Philip, for his part, knew the value of the English alliance and had no desire to break it; he was timid and slow, and endured a great deal from England in order to preserve friendly relations with her. But he was morbidly conscientious and honestly desired to make England a Roman Catholic kingdom.
Cecil fully understood Philip's position and shaped his own tactics accordingly. Whenever in his religious zeal Philip forgot his duties as a national king, that is, forgot what he owed to the commerce, industry, and general welfare of his people, and becoming the head of the Catholic league, plotted with the Catholics against Protestant England, Cecil did one of two things: either he drew near to France and aroused in Philip the fear of a political combination of England and France against Spain ; or he aided the Protestants in France, Germany, and the Netherlands and frightened Philip with the thought of a Protestant league that would oppose the Catholic league. Having by these means rendered Philip powerless, Cecil would then defy France by aiding the Protestants in Scotland, and so guard against a French invasion of Scotland, which for ten years was a real danger threatening Elizabeth. In the end he succeeded in driving the French from Scotland and won that kingdom to the Protestant cause. Thus Cecil's purpose was threefold: he was determined to maintain an alliance with Spain, to exclude the French from Scotland, and to prevent England from becoming involved in war either at home or abroad.
In his attempts to avoid war Cecil showed himself a master of diplomacy. In 1559 England and Spain were at war with France ; but the same year, at Cateau-Cambresis, France and Spain agreed to bring to an end the long struggle which had lasted off and on for forty years, and to this treaty England became a party.
Thus the peace of Cateau-Cambresis carried with it some disadvantages and dangers for England. In the first place, as the weakest and most dependent of the three powers, she was treated with least consideration. For instance, in order to obtain a peace which Cecil greatly desired and the exhausted condition of the treasury made imperative, Elizabeth was compelled to give up all hope of recovering Calais and to consent that France should hold the city for eight years, at the end of which time it should either be restored or paid for with five hundred thousand crowns of gold. In the second place, it involved England in a possible danger, for according to rumor Philip and Henry had not only formed a political alliance, but had also agreed to join in extirpating heretics.
The truth of this rumor has been denied; but Cecil believed it, and seeing only the danger, bent all his efforts to separate Spain and France. He knew that Philip had not been troubled seriously by Elizabeth's adherence to Protestantism, and would do anything to prevent England from falling into the hands of the French ; but he grew alarmed when Philip, after Cateau-Cambresis, married Elizabeth, daughter of Henry II of France. In order to mollify Philip, he proposed a marriage between Queen Elizabeth and Archduke Ferdinand of Austria, Philip's cousin; and at the same time, to arouse the jealousy of Philip, kept up the friendly relations with France. But the death of Henry II, in June, 1559, and the accession of Francis II and Mary Stuart changed the situation, for Francis and Mary at once assumed the title of king and queen, not only of France and Scotland, but of England also. Their claim to the throne of England was based on Elizabeth's illegitimacy; for if Henry VIII's marriage with Anne Boleyn were unlawful, Mary Stuart, according to the assertion of the Catholics, though not under the terms of Henry VIII's will, was the rightful heir to the throne. Had Mary Stuart's title been recognized, England, Scotland, and France would have been united under a single crown.
Cecil had to change his tactics. He knew that attempts to uphold Mary's title would be made by way of Scotland, and confident that Philip would not interfere, turned his attention, in the years 1559 and 1560, to the north, where he won his first great diplomatic victory.
