In March, Mr Kolomoisky was appointed by the Ukrainian government as regional governor of the important industrial region of Dnepropetrovsk, as the country's internal crisis escalated with the Russian takeover of Crimea.
But he has also been a player on the Euro-Jewish scene. In 2011, he and his compatriot, Vadim Rabinovich - who ran for Ukrainian president in the spring - founded the European Jewish Parliament to act as a voice for the continent's communities; they also started a Jewish news TV service which operated until spring this year when they turned their attention more to events in Ukraine .
Mr Bogolyubov is a major supporter of Lubavitch and founded a new Chabad community in Mayfair, central London after settling here. His charity distributed nearly £30 million from 2008 to 2012 with Anglo-Jewish causes among the beneficiaries.
Mr Kolomoisky's and Mr Bogolyubov's business association goes back more than 20 years and they helped to set up a banking group called Privatbank in 1992. In another High Court case, centring on a boardroom battle at a British oil exploration company called JKX, the judge last year noted that "Mr Kolomoisky, and probably Mr Bogolyubov, with him has a reputation as a corporate raider".
Victor Pinchuk, who made his fortune producing steel pipes and railway wheels in Europe, is a former Ukrainian MP. At one time, he was close to the centre of power and in 2002 married Elena, daughter of Leonid Kuchma, who was president of Ukraine from 1994 to 2005.
He has a taste for modern art and his philanthropy has included funding a film by Steven Spielberg about the Holocaust in Ukraine.
His legal claim arises from events 10 years ago when the Ukrainian government sold off most of a state mining enterprise.
Mr Pinchuk says that he reached an agreement at a meeting with Mr Kolomoisky and Mr Bogolyubov to provide funds for them to buy a stake in the mining business - but that they would transfer the shares to him at his request.
He paid $143million (£84 million) but, according to the court papers, says he ended up with a "worthless shell company", while the two other businessman controlled the mining shares.
But Mr Kolomoisky and Mr Bogolyubov deny any agreement over the shares. They argue that Mr Pinchuk owed them a substantial amount of money from a different business venture and the £84 million covered part of that debt.
The clash between oligarchs is not the only legal battle Mr Bogolyubov is involved in. He is facing a claim, filed at the High Court at the end of last year, from two business associates in the UK.
When Mr Bogolyubov moved to London with his family five years ago, he had already set up a charity foundation ahead of his arrival.
He had done so with the help of Rabbi Yonah Pruss, who had once run a Lubavitch support group for Soviet Jewry and who had been recommended to him by a leading rabbi in Ukraine.
Rabbi Pruss received £10,000 a month for running the foundation from May 2008 to July 2011, according to Mr Bogolyubov's defence papers. Among other things, Rabbi Pruss's duties included arranging "educational facilities for Mr Bogolubov's children" and "recommending kosher food suppliers".
The two men also had a business arrangement. Rabbi Pruss helped Mr Bogolyubov find properties for investment in the UK and brought in a property expert, Colin Gershinson, to assist. Mr Gershinson is a trustee of the Centre for Jewish Life, a Lubavitch-inspired but independent club for young adults in the West End of London.
Rabbi Pruss and Mr Gershinson were entitled to a share of the profits under certain terms. They say they helped Mr Bogolyubov buy more than a dozen properties around the country, including one in Knightsbridge for £56 million and another in Trafalgar Square for £173 million.
But Rabbi Pruss and Mr Gershinson say they were not paid all that was due, estimating that they are owed "in excess of £20 million". Mr Bogolyubov rejects the claim, arguing, in his defence, that the Knightsbridge and Trafalgar Square buildings were not part of the profit-share deal.
British courts have been a favourite sparring ground for Jewish tycoons from the former Soviet Union in recent years. The late Boris Berezovsky lost a claim against fellow expatriate, the Chelsea Football Club owner Roman Abramovich in 2012. Arkady Gaydamak failed in a claim against Lev Leviev over an African diamond deal in the same year.
