The Alt-Oldenburger and Ostfriesen are representatives of a group of horse breeds primarily from continental Europe called heavy warmbloods. The breed has two names because the same horse was bred in two regions in the most north-western part of Germany: East Frisia and the former grand duchy of Oldenburg. The name Alt-Oldenburger - alt meaning old - simply distinguishes this horse from its descendant the modern Oldenburg which is bred for sport.