Rubinstein was born into a dressage Royal Family. His dam is Antine, one of the three daughters of the mating of the Thoroughbred stallion, Angelo and Dodona (the two male foals from this pairing were Olympic dressage stars, Amon and Ahlerich). Rubinstein is by Rosenkavalier - Rosenkavalier is by Romadour II, who is the sire of World and Olympic champion, Rembrandt, out of Antine’s full-sister, Adone. From another full-sister, Annette came Romancier (also by Rosenkavalier) who stood at the Blue Hors Stud in Denmark. However it should be noted that Rubinstein’s two full-brothers have disappeared without trace.
Rubinstein was acquired at an early age by Mrs Gudula Vorwerk-Happ of the famous Vorwerk stud in Oldenburg.She bought him for a mere DM 35.000 as a three-year old. Before this he had been rejected for the Westphalian approvals, the commission being of the opinion that he was "too small, not enough horse, with defects on the hind leg not suitable for approval". De Baey had faith in the black horse, did not have him castrated and shortly afterwards welcomed Mrs Vorwerk and the Oldenburg Officials to his studfarm. Rubinstein was headed for Oldenburg.
Rubinstein was third in his performance test at Adelheidsdorf remarkably finishing in a higher position (4th) in the jumping rankings than he did in the dressage (5th).
Rubinstein was ridden in his early tests by that gifted rider/trainer Martina Hannöver, winning ten of his eleven starts at S-level. In 1995, Rubinstein scored eleven first and second placings at Grand Prix and Grand Prix Special level, and he was seriously being talked about as a candidate for the mighty German team to go to Atlanta. Then Martina lost the ride and Rubinstein went to Heike Kemmer, and the magic was lost. Nicole Uphoff rode the horse for a season, but even she could not get Rubinstein motoring again - his weaknesses, the lack of power and scope, particularly in the trot, were glaringly apparent.
Still, by this stage, Rubinstein’s most exciting son Rohdiamant, a foal from his first crop (out of Elektia V who is by the Anglo Arab stallion, Inschallah) was doing the performing for him. In 1993, Martina had ridden Rohdiamant into equal first place (with Wolkenstein II) in the 3 year old Championship at the Bundeschampionate.

Rohdiamant went on to be an exciting Grand Prix horse, ridden by the German based, US born, Lisa Wilcox, and just missed out on the American dressage team to go to the Sydney Olympic Games. He too is proving an exciting sire, with his son, Roman Nature winning the 3 year old Stallion title at the 1998 Bundeschampionate, and the 5 year old stallion class at the big stallion show at Zwolle. Rohdiamant’s full-brother, Royal Diamond (born in 1994) won the 5 year old championship at the Bundeschampionate and is now competing Grand Prix and in his first season scored a 69.5 in only his second ever Grand Prix Special.

In his second crop, Rubinstein sired Regazzoni (above) out of a Werther mare. Regazzoni was the champion of his stallion test at Münster-Handorf with a score of 140.53. Regazzoni is already the sire of a number of licensed stallions - and competed to FEI level himself, he looks (even to Nicole Uphoff) just like a stallion version of Rembrandt. He has recently been sold to the USA. Regazzoni semen was used for the first time in Australia in the 2000 season and the results have been quite good. Rubinstein has had at least two foals in Australia and a reported four pregnancies, but has not had a good striking rate. Rohdiamant has had very bad results, while Royal Diamond, his full brother, has been most successful.
Rubinstein is also the sire of Rotspon, born in 1995 out of a mare with classic Hannoverian bloodlines - Argentan, Pik Bube, Wendekreis. Rotspon topped his performance test in 1998 but sadly did not get a chance to compete at the Bundeschampionate, seemingly because Dr Bade did not wish to promote the son of a Westfalien stallion, standing at an Oldenburg stud. Like Weltmeyer, Rotspon produces wonderful semen, and frozen babies are springing up all over Australia.In Australia,

An Australian, Rubinstein son, Regardez Moi, who has been hugely successful in the competition arena with Heath Ryan and is now competing Grand Prix with a serious chance of a place in the team for the Beijing Olympic Games.

The most successful stallion son of Rubinstein in the competition arena has been Relevant, who with Lisa Wilcox in the saddle was a star in the American team at the 2002 WEG in Jerez. Rubinstein is also represented in the 2002 German team by the gelding, Renoir, with Ann-Kathrin Linsenhoff.