He remained at Dieppe, preaching, till the spring of 1558.
In Knox's absence even James Stewart and Erskine of Dun agreed to hurry on the marriage between Mary, Queen of Scots, and Francis, Dauphin of France, a feeble boy, younger than herself.

Their faces are pitiably young as represented in their coronation medal.
While negotiations for the marriage were begun in October, on December 3, 1557, a godly "band" or covenant for mutual aid was signed by Argyll (then near his death, in 1558); his son, Lorne; the Earl of Morton (son of the traitor, Sir George Douglas); Glencairn; and Erskine of Dun, one of the commissioners who were to visit France for the Royal marriage.
They vow to risk their lives against "the Congregation of Satan" (the Church), and in defence of faithful Protestant preachers.

They will establish "the blessed Word of God and His Congregation," and henceforth the Protestant party was commonly styled "The Congregation." Parliament (November 29, 1557) had accepted the French marriage, all the ancient liberties of Scotland being secured, and the right to the throne, if Mary died without issue, being confirmed to the House of Hamilton, not to the Dauphin.

The marriage-contract (April 19, 1558) did ratify these just demands; but, on April 4, Mary had been induced to sign them all away to France, leaving Scotland and her own claims to the English crown to the French king.
The marriage was celebrated on April 24, 1558.

In that week the last Protestant martyr, Walter Milne, an aged priest and a married man, was burned for heresy at St Andrews.