The Lyon-Caen & Thiriez firm of barristers to the Council of State and Supreme Court was established in 1957 by Arnaud Lyon-Caen.

It became a private professional company in 1978 and included two other partners, Louis Liard, replaced by Frédéric Thiriez in 1990, and Françoise Fabiani replaced in 2011 par Thomas Lyon-Caen.

In January 2016, Antoine Lyon-Caen becomes associated by the firm Lyon-Caen & Thiriez.

Antoine Lyon-Caen, Thomas Lyon-Caen et Frédéric Thiriez are now the three partners of Lyon-Caen & Thiriez firm of barristers.

The firm has twenty five permanent associate barristers and lawyers working on matters relating to public, private, criminal and international law.

The firm has a twofold representation and advisory role.


It fulfils its representation role before the following bodies:

- supreme bodies (Supreme Court, Council of State, Court of Arbitration)

- administrative bodies with general jurisdiction (administrative courts, administrative courts of appeal)

- specialist administrative bodies (Court of Audit, regional and local courts of accounts, Budget and Finance Disciplinary Court, disciplinary bodies, etc.)

- Constitutional Council

- independent administrative bodies (Competition Authority, Broadcasting Council, Banking Commission, etc.)

- international courts (European Court of Justice, European General Court, European Court of Human Rights, etc.)

Legal opinions

The firm also offers legal opinions without litigation.

It also offers training services that the associates are responsible for in their special areas of expertise.

Areas of expertise

With its multidisciplinary approach, the Lyon-Caen & Thiriez firm of barristers is in a position to offer a full range of legal assistance with regard to private, public, criminal and international law.

The firm also undertakes matters relating to domestic or internationalarbitration.


The firm’s clientele includes public bodies (central administrations, state establishments, local governments and groupings, local public establishments, public interest groups)and private bodies (enterprises, associations, organisations and private individuals).