Sumner Redstone, the media mogul who has called cut on Tom Cruise's relationship with Paramount Pictures, has weathered enough bruising personal battles — with his rivals, colleagues and family — to have little trepidation about taking on the gossip-ridden star.

Mr Redstone was born Sumner Murray Rothstein to a hard-working, ambitious family in Boston in 1923. After finishing top of his class at high school and studying at Harvard, Mr Redstone cracked Japanese codes during the Second World War and became a lawyer, working as a law secretary at the US Court of Appeals.

In 1954 he joined National Amusements Inc, the modest chain of cinemas and drive-in movie theatres that his father, a former linoleum and newspaper salesman, had built in Dedham, Massachussetts.

Over the next five decades, through investments in most of the major Hollywood studios and with the maxim "Content is king", Mr Redstone used National Amusements to grow one of the largest and most diverse media businesses in the world. In Forbes' 2006 list of the world's richest people, he ranked at number 63, with an estimate fortune of $7.7 billion.

(Tom Cruise, who remains Hollywood's most powerful star, is thought to be worth around $750 million and did not make the magazine's list of the 400 richest Americans.)

In 1987 Mr Redstone took control of Viacom, which owns cable television channels such as MTV, Nickelodeon and Comedy Central, before buying Paramount Pictures in 1993 and eventually merging Viacom back into CBS, its original parent company, in 2000. The combined empire of Viacom and CBS stretched from outdoor advertising across radio to publishing and television news before the two companies were separated again earlier this year.

Reviewers of Mr Redstone's 2001 autobiography, A Passion To Win, noted how keen he was to describe the many lasting friendships that have underpinned his career. But, like the rise of many Wall Street tycoons, its defining moments have been characterised by trouncing rivals as much as forging alliances.

The 1993 takeover of Paramount Pictures, for instance, was nearly derailed by a rival bid from Mr Redstone's so-called "best friend on the West Coast", Barry Diller. The acquisition became a vicious contest of bid and counter-bid, lawsuit and counter-lawsuit, with allegations of wiretapping, insider dealing and office break-ins that Mr Redstone later described as the "deal from hell".

The merger of Viacom and CBS, likewise, became swiftly darkened by the relationship between Mr Redstone and the CEO of CBS, Mel Karmazin, who became his number two at the new company. After four years of uneasy peace, and a series of apparently off-the-cuff, outspoken decisions by Mr Redstone, Mr Karmazin left.

"Viacom will always be controlled by... Sumner Redstone," Mr Kamarzin told Time magazine after he resigned in 2004.

Since then, and as a consequence of the increasing urgency of his succession plans, a feud has opened between Mr Redstone, who is 83, and his eldest son, Brent, who lives in Colorado and accuses his father of freezing him out of the family company.

Brent Redstone sued National Amusements in February, demanding control of his $1.3 billion stake in the company, which are currently held in a trust. His younger sister, Shari, is Mr Redstone's apparently favoured successor. She is chairwoman of National Amusements and vice chairwoman of both Viacom and CBS, where she is expected to become chairwoman.

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