Lord Thomas practiced at the commercial bar for 24 years before becoming a Judge of the Commercial Court in 1996, an appellate judge and Lord Chief Justice 2013-17. Lord Thomas has extensive experience as an arbitrator in commercial disputes, including as chair. Lord Thomas is President of the Qatar International Court, Chairman of London Financial Markets Law Committee, President of ARIAS (UK) and of the London Shipping Law Centre and First Vice-President of the European Law Institute (Vienna).