Although selection procedures had been in use for many years, the first Dutch horse registries weren't founded until the late 19th and early 20th centuries. The North-Netherlands Warmblood Horse Studbook, or NWP, regulated horse breeding in Groningen, Friesland, and Drenthe, while the NSTg did the same for the southern regions, including Gelderland. The goals of the registries were characterized by distinct differences in the soil composition: Groningen had heavy, wet, clay soil and needed a particularly stout horse to till it, while the soil in Gelderland was sandier.