Coat of arms of Denmark in the context of "Order of the Dannebrog"

The coat of arms of Schleswig or Southern Jutland (Danish: Sønderjylland or Slesvig ) depicts two blue lions in a golden shield. It is the heraldic symbol of the former Duchy of Schleswig, originally a Danish province but later disputed between Danes and Germans. The region has been divided between Germany and Denmark since 1920 and the symbol consequently appears in official heraldry in both countries. It is derived from the national coat of arms of Denmark and has been dated to the middle of the 13th century, first known from the arms of Erik Abelsøn, Duke of Schleswig. Throughout the ages, the design has featured both crowned and uncrowned lions, the lions have occasionally been accompanied by heraldic hearts, and usage between heraldic lions and leopards has shifted. The far most common version was to omit both crowns and hearts and this version has been used exclusively for several centuries.

The blazon in heraldic terms is: Or, two lions passant in pale Azure armed Or langued Gules.

The House of Estridsen was a dynasty that provided the kings of Denmark from 1047 to 1412. The dynasty is named after its ancestor Estrid Svendsdatter. The dynasty is sometimes called the Ulfinger, after Estrid's husband, Ulf Jarl. The dynasty also provided three medieval rulers of Sweden and one of Norway. Their family coat of arms became the coat of arms of Denmark and thereby influenced the coat of arms of Tallinn and the coat of arms of Estonia.

The Royal Court of Denmark does not differentiate between different royal houses among the early Danish kings, but uses the term "the descent of Gorm the Old" about all the pre-Oldenburg monarchs.