Abraham Frans Karel Hartogh (1844-1901).

• Profession: Lawyer.
• Relation to Mahler: One to the initiators and founders of the Amsterdam Royal Concertgebouw, who knew each other from the Old Exchange (Oude Beurs) in amsterdam, where they formed a “musical” group.
• Correspondence with Mahler: 
• Born: 29-12-1844 Amsterdam
• Died: 13-01-1901 The Hague
• Buried: 00-00-0000 

Amsterdam lawyer who belonged to the progressive liberals in the House of Representatives. Leading legal specialist, who through a legislative proposal brought about a comprehensive review of procedural law. Made the revision of a judgment possible following the so-called Hogerhuis affair (where two brothers were wrongly convicted for theft).