British people in average are mixture of Pre Indo-Eruopean people( north spain), Celts,Romans with large Germanic Input. this mixing is the reason we can find nordic and Britannic phenotype in single family. its similar to North India where 2 gracil or mixed skinned parents can give birth to nord-indid children.on average i believe east of England received more North Germanic people and duchy of kent received more farician people. Norman invasion also diluted large amount of Germanic blood and culture in England.

its safe to say that Bratian was a melting pot of various European races. while its not fully Germanic, its certainly a Nordic(North European country) country.