The White Rose of York a white heraldic rose

Rose (heraldry)

The rose is a common device in heraldry. It is often used both as a charge on a coat of arms and by itself as a heraldic badge. The heraldic rose has a stylized form consisting of five symmetrical lobes, five barbs, and a circular seed. The rose is one of the most common plant symbols in...

, is the symbol of the House of York

House of York

The House of York was a branch of the English royal House of Plantagenet, three members of which became English kings in the late 15th century. The House of York was descended in the paternal line from Edmund of Langley, 1st Duke of York, the fourth surviving son of Edward III, but also represented...

 and has since been adopted as a symbol of Yorkshire

Yorkshire

Yorkshire is a historic county of northern England and the largest in the United Kingdom. Because of its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform...

 as a whole.
Traditionally the origins of the emblem are said to go back to Edmund of Langley in the fourteenth century, the first Duke of York

Duke of York

The Duke of York is a title of nobility in the British peerage. Since the 15th century, it has, when granted, usually been given to the second son of the British monarch. The title has been created a remarkable eleven times, eight as "Duke of York" and three as the double-barreled "Duke of York and...

 and the founder of the House of York

House of York

The House of York was a branch of the English royal House of Plantagenet, three members of which became English kings in the late 15th century. The House of York was descended in the paternal line from Edmund of Langley, 1st Duke of York, the fourth surviving son of Edward III, but also represented...

 as a Cadet branch

Cadet branch

Cadet branch is a term in genealogy to describe the lineage of the descendants of the younger sons of a monarch or patriarch. In the ruling dynasties and noble families of much of Europe and Asia, the family's major assets – titles, realms, fiefs, property and income – have...

 of the then ruling House of Plantagenet

House of Plantagenet

The House of Plantagenet , a branch of the Angevins, was a royal house founded by Geoffrey V of Anjou, father of Henry II of England. Plantagenet kings first ruled the Kingdom of England in the 12th century. Their paternal ancestors originated in the French province of Gâtinais and gained the...

. The actual symbolism behind the rose has religious connotations as it represents the Virgin Mary, who was often called the Mystical Rose of Heaven.