Born on July 21, 1962 in Luxembourg. Luxembourg national. Lex has been admitted to the Luxembourg Bar in 1987.

He studied at the University of Paris I Panthéon-Sorbonne where he obtained his master’s degree in law (1st of the year 1985) as well as the European Community’s law study certificate (1st of the year 1985) and the diploma of specialized studies in private law (contract and responsibility, thesis on “loss of opportunity and risk creation”, 1st of the year 1986).

Lex was university tutor at the University of Paris I Panthéon-Sorbonne from 1986 to 1989 and lawyer and junior barrister in Luxembourg from 1987 to 1989. Has been attorney-at-law and solicitor since 1989 and opened his own law firm in 1990. Was appointed to the function of mediator in criminal matters by the Minister of Justice in 1999 and as honory consul of the Republic of Estonia in 2002.

Is a founder member and past president of the Federation of Free Radios, former vice-president of the Hispanic-Latin American cultural association ACHILA and founder member and former president of the Lions Club Viaduc as well as of the “Luxembourg Association of Maritime Interests”.

Speaks fluently Luxembourgish, German, French, English and Spanish and has knowledge in Italian, Portuguese and Russian.

Lex Thielen is specialized in civil law (with the accent on real estate, the construction law, the sale, co property law, the lease, inheritance and contracts), domiciliation of companies, corporate law, commercial law, financial law and economic criminality.

He is also the author of the books „Les professions de l’immobilier en droit luxembourgeois“ (“The real estate professions in Luxembourg law”, Larcier 2010), „ Le contrat de bail “ (Larcier-Promoculture 2013), „Tout savoir sur l’iimobilier“ (Promoculture Larcier 2014), „Immobilienrecht in Luxemburg- einfach erklärt“ (Promoculture-Larcier 2016) and “Le droit de la construction au luxembourg” (Promoculture – Larcier 2018)