The first incarnation of Viacom: Founded: December 31, 2005; 17 years ago () Founder: Sumner Redstone: Defunct: December 4, 2019; 3 years ago () Fate: Merged with the second incarnation of CBS Corporation: Successor: Paramount Global: Headquarters
It was established on December 31, 2005, as one of two companies which succeeded the original Viacom, alongside the second CBS Corporation. The controlling shareholder of both companies was National Amusements, a theater company headed by businessman Sumner Redstone.
The 2019 merger of CBS Corporation and Viacom was announced on August 13, 2019, and was completed on December 4, 2019. The merger of equals reunited CBS Corporation and Viacom into a single company known as ViacomCBS (today known as Paramount Global) after their separation from the first incarnation of Viacom on December 31, 2005.
Paramount Media Networks  (founded as MTV Networks in 1984  and known under this name until 2011; thereafter known as Viacom Media Networks until 2019) is an American mass media division of Paramount Global that oversees the operations of many of its television channels and online brands.
Background. The second incarnation of Viacom was established on December 31, 2005, after the original incarnation was split into two companies: one which retained the original Viacom name, and another one which was the original Viacom and was reincorporated into CBS Corporation.
The Viacom and CBS merger is complete. The Company is now known as Viacom Inc. The Viacom Board of Directors approves the creation of two separate publicly traded companies – CBS Corporation and Viacom Inc. Bob Bakish is named CEO of Viacom. Viacom and CBS reunite in $12 billion merger. ViacomCBS rebrands CBS All Access as Paramount+.
Viacom was split into the second CBS Corporation and Viacom incarnations — both remained under National Amusements ownership — in 2005;  the split was structured with the second CBS Corporation being the original Viacom's legal successor, and the second Viacom being an entirely new company. History