Swedish heraldry encompasses heraldic achievements in modern and historic Sweden. Swedish heraldic style is consistent with the German-Nordic heraldic tradition, noted for its multiple helmets and crests which are treated as inseparable from the shield, its repetition of colours and charges between the shield and the crest, and its scant use of heraldic furs. Because the medieval history of the Nordic countries was so closely related, their heraldic individuality developed rather late. Swedish and Finnish heraldry have a shared history prior to the Diet of Porvoo in 1809; these, together with Danish heraldry, were heavily influenced by German heraldry. Unlike the highly stylized and macaronic language of English blazon, Swedish heraldry is described in plain language, using (in most cases) only Swedish terminology. The earliest known achievements of arms in Sweden are those of two brothers, Sigtrygg and Lars Bengtsson, from 1219. The earliest example of Swedish civic heraldry is the city arms of Kalmar, which originated as a city seal in 1247. The seal (Swedish sigill), used extensively in the Middle Ages, was instrumental in spreading heraldry to churches, local governments, and other institutions, and was the forerunner of the coat of arms in medieval Sweden. Armorial seals of noblewomen appeared in the 12th century, burghers and artisans began adopting arms in the 13th century, and even some peasants took arms in the 14th century. Heraldry in Sweden today is used extensively by corporations and government offices; the rights of these private entities and of official bodies are upheld by Swedish law. In order to become legally registered and protected under Swedish law, an official coat of arms must be registered with the Swedish Patent and Registration Office (PRV), and is subject to approval by the National Herald (Statsheraldiker) and the bureaucratic Heraldic Board of the National Archives of Sweden. Heraldic arms of common citizens (burgher arms), however, are less strictly controlled. These are recognised by inclusion in the annually published Scandinavian Roll of Arms. Characteristics General features Swedish heraldry has a number of characteristics that distinguish the Swedish style from heraldry in other European countries. Common features of Swedish heraldry are similar to those of other Nordic countries and Germany, placing it in the German-Nordic heraldic tradition, distinguished from Gallo-British heraldry and other heraldic traditions by several key elements of heraldic style. One of these is the use of multiple helmets and crests, which cannot be displayed separately