Charles’s 55-year career in the law has combined extensive practice at the bar with distinguished public service, both national and international. For nearly 40 years he has focused on public international law and international dispute resolution.

As counsel or arbitrator he has handled cases on all six continents, principally under the rules of the ICC, UNCITRAL, LCIA, AAA, United Nations Compensation Commission, ICSID, Stockholm Chamber of Commerce, Insurance and Reinsurance Arbitration Society and LMAA. These cases have involved a wide variety of commercial disputes as well as issues of public international law, particularly involving the oil and gas sector, major infrastructural projects, expropriations, and other investment disputes, including ones arising under both bilateral and multilateral investment treaties.

Charles started his career with White & Case LLP in New York, before serving for four years in the United States Department of State in Washington, DC, concluding as its Acting Legal Adviser. He then rejoined White & Case LLP, co-founding its Washington, DC office, where his practice came to be comprised almost exclusively of substantial international arbitrations.

He has served continuously since 1983 as a judge of the Iran-United States Claims Tribunal in The Hague, The Netherlands. That service was interrupted for some months in 1987 by White House service as Deputy Special Counsellor to President Reagan. Charles resumed partnership in White & Case LLP from 1988 until joining 20 Essex Street in 2001. Since 2014 he has also served as a Judge ad hoc at the International Court of Justice.

In 2015 Charles was only the fourth ever recipient of the Global Arbitration Review Lifetime Achievement Award.