InBev is a subsidiary of Anheuser-Busch InBev. The company existed independently for several years - since the merger between Interbrew and Ambev and until the acquisition of Anheuser-Busch. InBev has operations in over 30 countries and sales in over 130 countries.
InBev was created in 2004 from the merger of the Belgian company Interbrew and the Brazilian company AmBev. Before the merger with Ambev, Interbrew was the third largest brewing company in the world by volume, Anheuser-Busch was the largest, followed by SABMiller in second place. Heineken International was in fourth place and AmBev was the world's fifth largest brewer.
Interbrew's roots can be traced back to 1366 in Den Horen in Leuven when the Artois brewery was founded. In 1987 Artois, and the Walloon-based brewer Piedboeuf, came together to form Interbrew. The move onto the international scene only happened when Interbrew acquired the Canadian beer brand Labatt. The transaction also included Labatt's sports-related assets, namely the Toronto Blue Jays baseball club, the Toronto Argonauts football club, and The Sports Network. At the time, Labatt was not much smaller than Interbrew, and since then the company has been considered a multinational with both Canadian and Belgian roots.
Some important Interbrew brands are Tennents, Stella Artois, Boddingtons, Beck's, Staropramen, Jupiler, Leffe, Labatt, Hoegaarden and Bass.
In December 2001 Interbrew, Danone (former owner of Kronenbourg, and two other smaller brewers) were fined €91m for operating a cartel in Belgium while four Luxembourg companies were fined €448,000 the same month.
AmBev was a Brazilian beer company formed by a merger in 1999 between the Brahma and Antarctica breweries. It had a dominant position in South America and the Caribbean
InBev announced in 2005 and confirmed in 2006 that it would move the brewing of Hoegaarden, whose brewery they found to have become obsolete, to the Piedboeuf brewery in Jupille, which resulted in huge protests and great disappointment in the town of Hoegaarden. The beer, though, is made with a very special yeast that is difficult to cultivate and keep alive (Just like the special Brussels' beer Geuze that no-one ever managed to brew outside Brussels). The Jupille-based brewery proved not being capable of attaining desired levels of quality and InBev's sole alternative was to bring production back to the original Hoegaarden-brewery, causing great sarcasm in the media that, by that time, had become openly hostile towards the beer-giant. In September 2007 however, it was announced that brewing would continue at the Hoegaarden Brewery in Hoegaarden.
On June 12, 2008, InBev announced that it has made a US$46 billion offer for the brewing firm Anheuser-Busch. If successful, it would join two of the world's four largest brewing companies (based on revenue) and create a company that brews three of the top beers in the world - Bud Light, Budweiser and Skol. InBev also stated that the merger would not result in any U.S. brewery closures and they would also attempt to keep on management and board members from both companies. 
On Sunday, July 13, 2008, Anheuser-Busch announced that they had agreed to an acquisition by Belgian brewer InBev valued at about US$52 billion in cash, or $70 per share. As a condition, InBev will be renamed Anheuser-Busch InBev and Anheuser-Busch would retain two seats on the board of directors.
Sources of Information
-  Wikipedia