Union mark of Norway and Sweden

It was inserted into the canton of the Swedish and Norwegian national flags from 1844 to denote the partnership of the two countries in a personal union.

A brief war with Sweden resulted in the Convention of Moss on 14 August 1814 and the Norwegian constitutional revision of 4 November 1814 to open the way for a personal union.

Public opinion in Norway saw this situation as unsatisfactory, and demanded a reform of flags and arms to reflect the equal status of the two states within the union.

In Sweden, it was always seen by some people as a desecration of their flag, and one of its adversaries called it "the herring salad"[7] (Norwegian: sildesalaten, Swedish: sillsalladen)[8] because of its resemblance to a popular dish on the Scandinavian smörgåsbord.

Radicals made it their political goal to reintroduce the "pure" Norwegian flag as the first step toward the dissolution of the union.

Finally, in 1898, the third royal veto was overruled and the union mark was removed from the national (merchant)[10] and the state flag.

By a royal decree of 27 October, the union mark in the merchant flag and the naval ensign was to be replaced with a blue field on 1 November 1905.

The union mark with proportions 5:4 used in Swedish flags
The square union mark used in Norwegian flags
The union naval jack and diplomatic flag of Norway and Sweden 1844–1905. The proportions 4:5 were those of the union mark in Swedish flags.
Norwegian herring salad, traditionally decorated with chopped egg yolks, egg whites, beetroots and parsley. The similarity of the decoration gave rise to the ironic nickname "the herring salad" for the union mark.