The Hell family estate on Horster Landstrasse was acquired by Gustav and Herta Hell in 1933.  Their younger son Max took over the existing poultry farm.  Their older son, Maas Johannes Hell (born in 1934), on the other hand, was soon to concentrate entirely on rearing horses.  He developed an area next to his parents' house for breeding horses, and established the business that he would run with his wife Magdalene, and which would soon become one of the best-known breeding establishments in Europe.

From 1971 to 1982 Hell led the association in Elmshorn and significantly influenced the development of sport horse breeding and the commercialisation of Holsteiner horses.  The involvement of stallions in sport and the importing of refining stallions, such as the legendary Cor de la Bryere, are enduring legacies of his clear-sighted work.

In 1982 Hell decided to give up the association's leadership, in order to develop and expand his private stallion station and business in Klein Offenseth.  This was the beginning of the Maas J. Hell Stud Farm in Klein Offenseth.  As a result, stallions that he had discovered could be found in almost all European breeding areas.  As a marketing manager too, his commercial successes speak for themselves.  Horses from Klein Offenseth were exported to 38 countries across the world, with many of these horses later going on to become adverts for the Holsteiner breed through their successes in the biggest tournaments.

In 1984 Maas Johannes Hell advertised for his six stud horses with a big advert in Pferd + Sport magazine.  As the business was not immediately suitable for a large number of mares to be covered because of space, initially only the two young stallions, Cantus and Camaro, were stationed in Klein Offenseth.  The four further stallions were accommodated in Dithmarschen with Lothar Völz in Wöhrden.  These horses were two sons of Alme, Ahorn and Athlet, as well as Latus from Landgraf and Catango from Caletto I.  The latter was changed in the following years for Fasolt and the thoroughbred Affido xx.  They remained until 1990, when they were moved to Marne – Westerdeich, to Willi Feil, who until 1995 accommodated Ahorn, Athlet, Latus and Salient xx at his station.

As the stallion stock grew continuously over the years, the Pohlsee Breeding Station was used in addition from 1989 to 1996.  First to come to this centre were Cantus, Langata Express xx and Aldan, and then, later on, Exorbitant xx, Tin Rocco and Alasca.

When, at the end of the 90s, artificial insemination and semen shipping became increasingly important, mares from the Hell stallions were inseminated at Tassemeier Veterinary Clinic in Wacken, as well as at Boje Peters' in Bargenstedt and in Rissum Lindholm.  For Maas Johannes Hell, the employment of thoroughbreds was particularly significant.  It began with Affido xx in 1987.  Then followed Salient xx, Exorbitant xx, Bold Indian xx, Langata Express xx, Gamblers Cup xx and Mytens xx.  A particularly fortunate discovery was Lauries Crusador xx.   Thanks to good links with “Landstallmeister” Dr. Bade, Lauries Crusador xx was leased to the Lower Saxony County Stud Farm in Celle and moved to the major Hannoverian breeding region in Landesbrück in 1991.  In 2006 he was awarded the title 'Hannoverian Stallion of the Year'.

With this stallion it also came to be that the Hell stallions were distributed through the Lower Saxony County Stud Farm.  Stallions Calido I, Acord II and Acorado had a strong influence on the Hannoverian breed.

Maas Johannes Hell has always paid careful attention to the offspring of his stallions.  Each year he bought several of their foals.  These were then reared in Klein Offenseth and either prepared as young studs or launched as sport horses.  A number of important sport horses have come form this collection of offspring, including Calvaro with Willi Mellinger, Canturo with Bernado Alvares, Lux with Jerry Smit and Libero with Jos Lansink.

The stud farm in Klein Offenseth has become renowned across the world, not only because of the outstanding hippological personality of Maas Johannes Hell, but also because of the stallions themselves.  At the pinnacle we have, alongside their fathers, Ahorn's son Acord II and, from Cantus, the stallion Calido I.  Both of them radiated brilliance with convincing stallion performance inspections.  Their careers in show jumping events were exemplary.  They were serial winners in show jumping events to Class M.  Acobat was Holsteiner Show Jumping Champion in Bad Segeberg and runner up at the Federal Championships.  With 21 victories, he was the most successful stallion in Germany for five years.  The offspring of these two exceptional sires are also of an extremely high quality.  In 1999 a child of Acord II triumphed at the German Show Jumping Horse Championships in Warendorf.  And Calido I has also developed into a first-class show jumping sire.  In 2008 three of his offspring took part in the Olympic Games in Peking.

Maas Johannes Hell passed away in 1997.  His wife continued to run the business, along with long-term trainer Thomas Mohr, who went his own way some years earlier.

At the start of 2011 Magdalene Hell decided to place the station into the hands of Hamburg businessman Herbert Ulonska, who for decades had already been making a name for himself in Germany through his involvement with stallion breeding/leasing and the organisation of international tournaments, and even today achieves success in tournaments as an amateur, up to S Class, with his own stallion.  The most successful horses remained at the station, including Calido, Acodetto, Ramirado, Canturo and Singulord Joter.  In addition, Canstakko, Chupamint, Lentini, Levinus and Class de Luxe, amongst others, stayed on.  Herbert Ulonska will continue to lead the stud farm in the spirit of Maas J. Hell, who truly shaped the landscape of private stallion rearing in Schleswig-Holstein.