A subsidiary of Norsk Hydro, the company was founded in 1907 and operated until 1991.

In 1951, a German subsidiary was founded, Ehapa.

Its subsidiary, Discovery Clinical Trials, was founded in 2008.

In 1964 and 1966, subsidiaries were founded in Brazil and Mexico.

Strong demand meant the company expanded rapidly and within three years the first subsidiaries were founded in Brazil and France.

In 1994, a subsidiary of Acorn, Online Media, was founded.

The subsidiary was founded in 1994.

Similar subsidiaries were later founded worldwide.

A children's subsidiary of Bloomsbury USA was founded in 2002.

The subsidiary was founded on April 18, 2007 but the site did not go live until May 2008.