Redstone and Viacom Executives Go to Court Against Each Other

The vicious battle over the future of Sumner M. Redstone’s $40 billion media empire boiled over from the public stage into courtrooms on both coasts Monday. With sharp rhetoric, directors from Viacom, Mr. Redstone’s entertainment company, charged in a lawsuit that the media mogul had been manipulated by his daughter, Shari Redstone, into changing the terms of the trust that controls his companies. Philippe P. Dauman, the chairman and chief executive of Viacom, who was removed from the trust, called it an “an unlawful corporate takeover.” Mr. Redstone’s legal team fired back with a petition in Los Angeles, asking that a court confirm the validity of the changes he made. Mr. Redstone’s lawyer said his client was “saddened that Mr. Dauman is trying to make this dispute” about Mr. Redstone’s daughter.