Many of the common people in the UK were actually the hunter-gatherers who were dark skinned, meat eating, light-eyed. Then, as they moved to agriculture with the addition of Iranian neolithic farmers, they lost the Vitamin D from the animal diet and the lighter skinned (low melanin) survived
So most of these people were "Stonehenge builders", then "Celts", then "Anglo-Saxons", then "English"
Genetic studies suggest Celtic populations arose from a mix of indigenous European hunter-gatherers, Neolithic farmers, and Indo-European pastoralists from the Pontic-Caspian steppe (Yamnaya culture, c. 3000 BCE). The spread of Celtic culture likely involved both population movements and language diffusion.
Bohemia is derived from a name of a Celtic tribe - these people spread outwards towards France, Spain, the British isles, then also to Turkey and Italy devastating Rome in the 4th century BC, and Anatolia shortly afterwards (the origin of the Galatians)
But genetically they are this mix of hunter-gathers, Iranian neolithic farmers and an overlayer of Indo-European steppe warriors
