Valdemar's position was still further strengthened when Frederick II., the successful rival of Otto IV., was, in 1215, crowned at Aix-la-Chapelle.
Very different was Valdemar's second conference with Barbarossa, on the banks of the Eider, in 1182, when the two monarchs met as equals in the presence of their respective armies, and a double marriage was arranged between two of Valdemar's daughters and two of the emperor's sons.
The only serious domestic trouble during Valdemar's reign was the rebellion of the Scanian provinces, which objected to the establishment of a strong monarchy inimical to local pretensions and disturbances, and especially to the heavy taxes and tithes necessary to support the new reign of law and order.
Valdemar's worst faults were a certain aloofness and taciturnity.
(1340), who for nine years had held Jutland and Funen and dominated the rest of Denmark, first opened Valdemar's way to the throne, and on midsummer day 1340 he was elected king at a Landsting held at Viborg, after consenting to espouse Helveg, the sister of his most important confederate, Valdemar, duke of Schleswig.
Neither the time nor the place of Valdemar's birth is known, but he could not have been more than twenty when he became the nominal king of Denmark, though, as a matter of fact, his territory was limited to the northernmost county of Jutland.
At a Hansetag held at Cologne on the 11th of November 1367, three groups of the towns, seventy in number, concerted to attack Denmark, and in January 1368 Valdemar's numerous domestic enemies, especially the Jutlanders and the Holstein counts, acceded to the league, with the object of partitioning the realm among them.
Valdemar's skilful diplomacy, reinforced by golden arguments, did indeed induce the dukes of Brunswick, Brandenburg and Pomerania to attack the confederates in the rear; but fortune was persistently unfriendly to the Danish king, 1 Rostock, Greifswald, Wismar and Stralsund.
Valdemar's son, Eric Plovpenning, succeeded him as king; but his near kinsfolk also received huge appanages, and Period of family discords led to civil wars.
The keystone to the whole constitutional system was " King Valdemar's Charter "issued in May 1360 at the Rigsmiide, or parliament, held at Kalundborg in May 1360.