most powerful families in Europe and the owner of the finest art collection in the world, is today to plunge into a legal battle with his eldest son over a fortune worth $2.7 billion.

The case promises to reveal intimate details of a bitter feud between Georg (Heini Jr.) and the baron (Heini Sr.) and his present wife, a former Spanish beauty queen.

The frail 78-year-old baron is trying to wrest back control from his son, whom he put in control of a Bermuda-based trust in 1983.

No expense has been spared on the case with dozens of lawyers and support staff flown in to Bermuda.

It has taken a year and a half for the lawyers to sort out preliminary legal wrangles, and today the court case will begin in earnest for the first time.

The baron accuses his son of threatening the interests of his other heirs, including his wife, Carmen "Tita'' Cervera.

"If I do not do this, there would be a long, hard legal battle after my death,'' he said a year ago.

"I would not advise anyone to do what I did. You should never give out legacies before you are dead.'' Apart from 49-year-old Heini Jr., the baron has four children who stand to inherit millions after his death.

There are fears that the baron, whose health is fragile after a stroke in 1994, will not survive the court case.

Relations between father and son began to deteriorate in 1996, and the baron claims that since 1995 his son has not paid him 40 million gilders a year that was agreed upon when he handed the business over to his son.

In the court today, the baron's lawyers will argue that Heini Jr. owes him $70 million in arrears.

The Thyssen empire was founded by the baron's grandfather, August, known as the King of the Rhur and consolidated by his father, Heinrich and his pro-Nazi uncle Fritz.

Heinrich married an impoverished Hungarian aristocrat and had himself adopted by her family so he could inherit the Thyssen-Bornemisza title.

He built up an art collection which rivals that of the Queen of England and the baron, no stranger to the courtroom, took his three brothers and sisters to court to try and keep the collection together.

When he failed, he religiously bought back each piece and added to the collection himself.

The baron inherited shipping and banking interests from his father and built up his own wealth through astute investment in the 1960s.

He retired from running his business in the mid-eighties and named his eldest son the executive president of the Thyssen-Bornemisza Group.

made up of interests in mines, shipping, information systems and plastics around the world. Last year the company earned $100 million and has annual sales of $2 billion.

In a letter to his other children the baron has been explicit about what he sees as Heini Jr.'s greed.

It said: "I want you to know that it remains my intention that each of my children should obtain his or her proper share of my assets upon my death. At present Heini junior has manoeuvred himself into a position where, in the absence of action on my part, he would get far too much.'' Among those whose interests the elder Thyssen is fighting for are 18-year-old Borja, Tita's illegitimate son, who has been adopted by the baron.

Monaco-based Heini Jr. was the fruit of the baron's first marriage to Maria Teresa de Lippe.

In between the baron had two children with his third wife, a Scottish model, Fiona Campbell, and another with his fourth wife Denise Ssshorto, a Brazilian.

In 1993 he sold his art collection -- one of the largest in the world to be in private hands -- to the Spanish government for $350 million. The collection in housed in Madrid in the Thyssen-Bornemisza museum. If the baron succeeds in his court case and the Bermuda trust is dissolved, then the collection may become part of the dispute.

BUSINESS BUC