Vodafone acquired Mannesmann in 2000 in the largest corporate takeover at the time.
The hostile takeover battle began when Vodafone made an approach to Mannesmann, a German conglomerate with a rapidly expanding mobile-telecommunications business. Mannesmann initially resisted, but the companies reached an agreement in February 2000. The transaction was valued at roughly €180 billion, or about $183 billion at the time, depending on the exchange-rate calculation used.
The deal was especially significant because it represented a British company taking over one of Germany's largest corporations. It also showed how valuable mobile-phone licenses and subscriber growth had become during the late-1990s telecommunications boom.
After the acquisition, Vodafone focused on telecommunications and sold or separated many of Mannesmann's non-telecom activities. The transaction is sometimes called a merger, but Vodafone was the acquiring company. Its scale made it a landmark European takeover even before later mega-mergers changed the rankings.