Red hair has long been associated with Celtic people. Both the ancient Greeks and Romans described the Celts as redheads. The Romans extended the description to Germanic people, at least those they most frequently encountered in southern and western Germany.

Why did Celts have red hair?

Cloudy weather could have caused Celts' red hair

Essentially, this means that red hair helps to take advantage of sunny days and allows the body to absorb more vitamin D.

Are Celts redheads?

Redheadedness is a north and western European trait, but the pattern of redheads in the British Isles is more consistent with the ancient indigenous Celtic inhabitants who were here before the Vikings and the Anglo-Saxons. ... Red hair is caused by V60L allele – 'the ginger gene'.