The Danish intervention in the Thirty Years War, the Kejserkrigen, began in 1625. After Dessau and Lutter am Barenberge, in 1626, Tilly and Wallenstein occupied Holstein and Jutland, as far as the Limfjord. Christian IV's fleet held the islands. In 1628, landings on the Baltic shore; Wallenstein failed at Stralsund; at Wolgast, in August, the Danes lost. Talks at Lübeck from January 1629; secret ones at Gustrow. The instrument was signed on 22 May 1629, at Lübeck. For the king: Christian IV. For the emperor: Albrecht von Wallenstein. Ferdinand II ratified on 7 June. The Catholic League was a formal party. The language was German.

First: everlasting friendship by sea and land; what had passed is wiped out. Christian will meddle in the affairs of the Reich only as a prince and estate, by reason of the duchy of Holstein, and will no longer claim archbishoprics and stifts for himself or his sons. The emperor, for his part, will not meddle in the sovereign Danish kingdoms. Disputes, amicably or by arbitrators.

Second: the claim for war costs is dropped on both sides. The occupied provinces — Vendsyssel, Jutland, Schleswig, Holstein, Stormarn, Dithmarschen — are restored with all regalities, fortresses and towns, reserving imperial overlordship and feudal right in Holstein, Stormarn and Dithmarschen. Imperial troops leave at once, without exactions. Confiscation proceedings are abolished. The religious and profane peace is left standing.

Third: prisoners are released without delay. Fourth: on the imperial side Spain, Poland, the Infanta at Brussels, the House of Austria, Bavaria and the obedient estates may be included; on the Danish side France, Great Britain, Sweden and the United Provinces, if they wish. Fifth: the islands of Fehmarn, Nordstrand, and the shares on Fohr and Sylt are restored to the Gottorp line, reserving Danish rights; the troops withdrawn; no revenge on the princes of the Reich for what happened in the war.

This is not the Peace of Westphalia. The Edict of Restitution, issued by Ferdinand during the talks, hit northern Germany without a Danish shield. Sweden landed in Pomerania in 1630. The cover is the 1629 portrait of Christian IV at Koldinghus, from the year of the peace; the title leaf of the 1629 print is too narrow.

Sources: Treaty of Lübeck; Friede von Lübeck.