Marius Kohl (born 16 September 1953)[1] is the former chief of the Luxembourg tax agency Sociétés 6.[2][3] During his 22-year tenure, he was solely responsible for approving thousands of tax arrangements for foreign companies investing capital in Luxembourg. He retired in 2013.[2] Kohl was known by the nickname "Monsieur Ruling" and has been credited with helping to secure €1.2 billion in annual tax revenue for Luxembourg.[3]