Blanche, derived from the French word 'blanc', meaning white, is a feminine given name that was popularized during the Middle Ages through the character of Blanchefleur in the French epic poem 'Roman de la Rose'. It was also made prominent by Queen Blanche of Castile, mother of Saint Louis IX of France. The name was subsequently adopted in other European languages and cultures, with variants such as Blanca (Spanish), Bianca (Italian), and Blanka (Czech).
"Blanche was a popular name for girls from the late 19th to mid-20th century, with peaks of popularity around 1918 and again in the early 1930s."