Walgreen Co., the largest drugstore chain in the US, announced today that it will buy the remainder of Alliance Boots, Ltd.

Walgreen already owns 45% of Alliance Boots that was purchased in 2012 with the goal of creating a global chain, but will now purchase the remaining 55% with a deal somewhere in the ballpark of 5-6 billion pounds ($8 billion to $10 billion USD). Alliance Boots has both beauty and pharmacy stores in Europe, so Walgreen’s acquisition of the remaining half of the company expands its presence in Europe overnight. The acquisition could be completed for as much as $16 billion.

Prior to the announcement, Walgreen had considered moving its headquarters overseas in an effort to dodge the 35% corporate tax fee on its business. The company’s now announced that it will retain its corporate tax headquarters in the US. Apple Inc. has also moved a considerable amount of income to its Ireland dummy corporation because of the high corporate tax fee in the US and came under scrutiny by the US Senate last summer for what some believed to be tax evasion. Walgreen and Alliance Boots were in discussions as early as June about what would take place during and after the acquisition.

Alliance Boots is a British pharmacy and beauty company that was founded in 2007 when pharmacy company Boots Group and pharmacy company Alliance UniChem merged in 2006. The company reported a revenue of 23.4 billion  pounds in the 2013-14 sales season.

Walgreen’s recent acquisitions make it clear that the company wants a Walgreen store on every corner, every street, every place possible. The company also purchased North Carolina-based Kerr Drugs within the past year, and currently owns about 8,200 drugstores in the United States. The company’s overall sales increased between $6.1 and $6.4 billion in July 2014.