Horse Color Genetics in the Iron Age/Medieval Age
As horse domestication became more popular, even more, unique phenotypes began to emerge. During the Iron/Medieval Age, older phenotypes such as Bay and Black began to decrease as more colorful and unique coat colors grew more popular. Buckskin and Silver-Black alleles appeared, and phenotypes that had the functional Sabino and Tobiano alleles increased in frequency due to selective breeding by mankind.
No viable fossils were found in Europe around this time period, so not much is known regarding the European horse genotypes of this period. However, because the fossils in Europe and Asia followed a similar pattern, we can assume that horses in Europe had similar genotype proportions to that in Asia during the Iron/Medieval Age.