On June 17, 1397, Margaret summoned to an assembly at Calmar, in the province of Smaland, Sweden, the clergy and the nobility of Denmark, Norway, and Sweden, and established, by their aid and consent, a fundamental law. This was the law so celebrated in the North under the name of the "Union of Calmar," and which afterward gave birth to wars between Sweden and Denmark that lasted a whole century. It consisted of three articles. The first provided that the three kingdoms should thenceforward have but one and the same king, who was to be chosen successively by each of the kingdoms. The second article imposed upon the sovereign the obligation of dividing his time equally between the three kingdoms. The third, and most important, decreed that each kingdom should retain its own laws, customs, senate, and privileges of every kind; that the highest officers should be natives; that any alliance concluded with foreign potentates should be obligatory upon all three kingdoms when approved by the council of one kingdom; and that, after the death of the King, his eldest son, or, if the King died childless, then another wise, intelligent, and able prince, should be chosen common monarch; and if anyone, because of high treason, was banished from one kingdom, then he should be banished from them all. A month after, on the Queen's birthday, July 13th, a legitimate charter was drawn up, to which the Queen subscribed and put her seal; on which occasion Eric of Pomerania was anointed and crowned by the archbishops of Upsala and Lund as king of Denmark, Norway, and Sweden. The _Te Deum_ was sung in the churches of Calmar, the assembly crying out: "_Haecce unio esto perpetua! Longe, longe, longe, vivat Margarethe, regina Daniae, Norvegiae et Sveciae!_" This strict union of the three large states became a potent bulwark for their security, and made them, in more than one century, the arbiter of the European system; the three nations of the northern peninsula presenting a compact and united front, that could bid defiance to any foreign aggression.