Hessian boots are an old style of boots that gained great popularity in the mid 18th century; however quickly fell out of favor as advances in material technology made them obsolete.
Named for Hess Germany, these boots gained popularity as standard issue items for military personnel, but quickly gained wider appeal among civilians due to their practical implications. Hessians have a low heal that makes walking and running comfortable, as well as a semi pointed toe allowing them to work well in stirrups. Hessians had the added benefit of reaching to the bottom of the knee; thus protecting the lower leg.
Today hessian boots are not widely seen. They have largely been replaced by Wellington Boots and cowboy boots; each of which evolved from the same basic idea of the hessian, however added extra design implementations to make them more appropriate for the needs of their time.