Coat of arms of Luxembourg

The coat of arms of Luxembourg has its origins in the Middle Ages and was derived from the arms of the Duchy of Limburg, in modern-day Belgium and the Netherlands. In heraldic language, the arms are described as: Barry of ten Argent and Azure, a Lion rampant queue forchée Gules crowned, armed and langued Or.

Versions
There are greater, middle and lesser versions of the coat of arms of Luxembourg. The greater coat of arms has two reguardant and crowned lions as supporters, the Dynastic Order (the Order of the Oak Crown) and all surrounded by ermine mantling crowned with a heraldic royal crown (the crown used by the Grand Duke). The middle coat of arms has the supporters and the crown. The lesser coat of arms has the crown and the escutcheon without external ornaments.

Arms of the monarch
The Grand Duke has a personal coat of arms, the current arms were adopted in 2001:

Quarterly: 1 and 4 Luxembourg, 2 and 3 Nassau (Blazon: Azure billetty Or, a lion or armed and langued Gules). The lesser variant of the arms of the monarch has no external ornaments. The middle variant has the supporters and the crown.

The greater variant has a dynastic inescutcheon with the arms of the House of Bourbon-Parma (Blazon: Azure bordure Gules charged with eight escallops Argent, three fleurs-de-lys Or). The supporters are holding a lance Or, flying the flag of the Netherlands, all surrounded by ermine mantling with the crown.

Historical
The coat of arms adopted by Grand Duke Adolphe in 1898:

Arms of the Hereditary Grand Duke
The current greater and lesser coats of arms for the Hereditary Grand Duke are currently prescribed by grand-ducal decree of 31 October 2012 and are similar to that of the Grand Duke's with the addition of a gold label on the shield for differencing. In the greater arms, the supporters also do not carry flags.

The coat of arms of Henry V, Count of Luxembourg (1216–1281)
Henry V was the first Count of Luxembourg to adopt these arms (the "Lion of Luxemburg"). His father, Waleran III, Duke of Limburg, bore the arms Argent, a lion rampant queue fourchée gules armed langued and crowned or (white field bearing a red double tailed lion with yellow claws, teeth, tongue and crown), generally known as the "Lion of Limburg". Henry V replaced the field argent (white) with barry argent and azure (a series of alternate white and blue bars, numbering 8 or 10), to difference his arms from his half-brother Henry IV, Duke of Limburg.

It is uncertain what was the origin of this field barry argent and azure. Jean-Claude Loutsch, Luxembourg's most prominent heraldist, suggested the theory that the original Luxembourg dynasties may have born a barry banner (colours unknown). Two dynasties closely related to the first Houses of Luxembourg also adopted barry coats of arms during this period, namely the Counts of Loon and the Counts of Grandpré bore the arms Barry of ten or and gules (10 yellow and red alternating bars). In such a case, the choice of colour of the bars would have been selected to match the white field and red lion of Limburg.

The coat of arms of Henry VI, Count of Luxembourg (1240-1288)
In 1282, after the death of Waleran IV of Limburg, Henry VI, count of Luxembourg changed his arms by doubling the lion's tail and passing it in saltire as a claim on the duchy of Limburg. After Henry VI's death in 1288 at the Battle of Worringen, Henry VII readopted his grandfather Henry V's arms, which remained in use until the extinction of the House of Luxembourg.

Lusignan and Stratford
The Luxembourg Coat of Arms bears a striking similarity to both the arms of Lusignan and of Stratford. The relationship is unknown, if indeed any exists at all although the link between the Lusignan and Luxembourg coat-of-arms is provided in 'Le Roman de Mélusine' by Couldrette whereby a descendant of the legendary founder and faerie queen of Lusignan adopts the burely of 10 argent and azure, adding the lion rampant due to his similarly shaped birthmark. Historians have generated various theories as to the connection between the houses and the arms, none conclusive.