[3] In 1999, six European law firms with 1,400+ lawyers and roughly DM 500 million in joint revenues came together to form CMS.

[9] Initially, CMS included law firms from Germany, the Netherlands, Austria, and the United Kingdom, among others.

[21][22] Carter-Ruck was involved in legal action against Financial Times journalist Catherine Belton and her publisher HarperCollins over her book Putin's People.

[23] In April 2022, CMS law firm was named alongside Harbour Litigation Funding by Kevin Hollinrake MP, in a letter to the Chancellor of the Exchequer Rishi Sunak MP, as two professional services firms acting for the benefit of Russian state entities during the invasion of Ukraine.

As a not for profit entity, it is financed by means of revenue contributions from the participating law firms, which remain legally independent.

[27] Currently, CMS has 18 member firms with main headquarters in twelve European, four South American and two African countries.