Maximilian Maria was the elder of the two sons of Maximilian Anton Lamoral, Hereditary Prince of Thurn and Taxis and Duchess Helene in Bavaria. After the death of his father on 26 June 1867, he became heir apparent to the headship of the House of Thurn and Taxis. With the death of his grandfather Maximilian Karl, 6th Prince of Thurn and Taxis on 10 November 1871, he succeeded as Prince of Thurn and Taxis at the age of nine.
