Editing Frederick III of Denmark (section)

=== Defeated by Sweden ===
{{Main|Dano-Swedish War (1657–1658)|Treaty of Roskilde}}
[[File:Treaty of Roskilde - peace banquet.jpg|thumb|180px| The peace banquet (Fredstaffelet) at Frederiksborg Castle following the signing of the Treaty of Roskilde in 1658.]]
With all his good qualities, Frederick was not a man to recognize fully his own limitations and that of his country. But he rightly regarded the accession of [[Charles X of Sweden]] on 6 June 1654 as a source of danger to [[Denmark-Norway]]. He felt that temperament and policy would combine to make Charles an aggressive warrior-king: the only uncertainty was in which direction he would turn his arms first. Charles's invasion of [[Poland]] in July 1655 came as a distinct relief to Frederick, even though the [[Second Northern War|Polish War]] was full of latent peril to Denmark. Frederick was resolved upon a rupture with Sweden at the first convenient opportunity. When ''Rigsdagen'' assembled on 23 February 1657, it willingly granted considerable subsidies for mobilization and other military expenses. On 23 April he received the assent of the majority of ''Rigsraadet'' to attack [[Dominions of Sweden|Sweden's German dominions]]. In the beginning of May, the still pending negotiations with that power were broken off, and on 1 June Frederick signed the manifesto justifying a war, which was never formally declared.<ref name="Britannica" />

The Swedish king confounded all the plans of his enemies with the [[March across the Belts]] in January and February 1658. The effect of this unheard-of achievement of crossing the frozen sea to invade Danish territory was crushing. Frederick at once sued for peace. Yielding to the persuasions of the [[England|English]] and [[France|French]] ministers, Charles finally agreed to be content with mutilating, instead of annihilating, the Danish monarchy. The [[Treaty of Taastrup]] was signed on 18 February and the [[Treaty of Roskilde]] on 26 February 1658. The conclusion of peace was followed by a remarkable episode. Frederick expressed the desire to make the personal acquaintance of his conqueror and Charles X consented to be his guest for three days, 3 to 5 March, at [[Frederiksborg Palace]]. Splendid banquets lasting far into the night and intimate conversations between princes who had only just emerged from a mortal struggle seemed to point to nothing but peace and friendship in the future.<ref name="Britannica" />