The battles even extend to within his family where the matter of succession is a source of tension. When Redstone eventually steps down, the job of chairman will probably pass either to Freston, or to Les Moonves, who heads CBS, which was spun off from Viacom in January. But to maintain blood control in the boardroom, Redstone has let it be known that the 70 per cent of Viacom voting shares he owns will pass to his daughter, Shari, 52, who is already on the board. Redstone has a son, Brent, whohas been effectively frozen out of Viacom. In a fit of pique over succession arrangements he filed a lawsuit against his father and Shari this year in an attempt to reclaim what he believes should be a $1bn slice of the family pie.