The Oldenburg is a warmblood horse from the north-western corner of Lower Saxony what was formerly the Grand Duchy of Oldenburg. The breed was built on a mare base of all-purpose farm and carriage horses today called the Alt-Oldenburger. The modern Oldenburg is managed by the Association of Breeders of the Oldenburger Horse which enacts strict selection of breeding stock to ensure that each generation is better than the last.