Relations between France and England are collapsing by early 1543.

Henry is already angered by Francis’s refusal to pay the various pensions, which are owed to him under the terms of past treaties.

He is now faced with the potential of French interference in Scotland, where he is entangled in the midst of an attempt to marry his son to Mary, Queen of Scots, which will develop into the open warfare of the "Rough Wooing.”

He had intended to begin a war against Francis in the coming summer, but negotiating a treaty to this effect with Emperor Charles V proves difficult.

Because Henry is, in Charles's eyes, a schismatic, the Emperor cannot promise to defend him against attack, nor sign any treaty which refers to him as the head of the Church—both points upon which Henry insists.

Negotiations continue for weeks; finally, on February 11, 1543, Henry and Charles sign a treaty of offensive alliance, pledging to invade France within two years.