After completing his secondary education exams at the Wilhelmsgymnasium in Munich he studied law in Munich and Prague. From 1941 until 1946 he was in exile in Iceland owing to the events of World War II.
In 1946 he first became a member of the CSU. In spring of 1947 he, alongside Anton Donhauser and other members and functionaries, left the CSU for the Bavaria Party. This was due to disappointment with the Schäffer-Hundhammer-wing of the CSU not having been able to implement enough policies focused upon Bavaria-centric issues. Within the same year he became the regional chairman of the Bavaria Party in Niederbayern.
From 1949 until 1953 von Aretin was a member of the German Parliament, in which he represented the Bayern Party. From 14 December 1951 the Bayern Party would go on to form the Föderalistische Union faction with the Centre Party (Germany). He was later a member of the Landtag of Bavaria from 1950 until 2 May 1951, in which he represented the locality of Vilshofen an der Donau.
From 1954 until his sudden death, he worked for Aldersbach brewery and supposedly contributed to their success. In 1969 he married the Austrian Johanna Colloredo-Mansfeld (1923–2010).
Deutscher Bundestag (Hrsg.): Datenhandbuch zur Geschichte des Deutschen Bundestages von 1949 bis 1999. Eine Veröffentlichung der Wissenschaftlichen Dienste des Deutschen Bundestages. Nomos, Baden-Baden, ISBN 3-7890-5928-5.
Rudolf Vierhaus, Ludolf Herbst (Hrsg.), Bruno Jahn (Mitarb.): Biographisches Handbuch der Mitglieder des Deutschen Bundestages. 1949–2002. Bd. 1: A–M. K. G. Saur, München 2002, ISBN 3-598-23782-0, P. 18.
Wessel (from 14 December 1951 FU, from 13 November 1952 Non-attached (GVP))
Willenberg (from 26 October 1950, from 14 December 1951 FU)
DRP
DRP
Members:
Dorls (from 13 December 1950 WAV-Gast, from 17 January 1951 WAV, from 26 September 1951 Non-attached, am 23 October 1952 Mandatsaberkennung)
Frommhold (from 7 September 1949 Nationale Rechte, from 5 October 1950 Non-attached (DRP), from 26 March 1952 DP-Gast, from 11 February 1953 Non-attached)
Miessner (from 5 October 1950 FDP-Gast, from 20 December 1950 FDP)
Rößler (from 15 September 1949 Nationale Rechte, from 6 September 1950 Non-attached, from 13 December 1950 WAV-Gast, from 17 January 1951 WAV, from 26 September 1951 Non-attached, until 21 February 1952)
Thadden (from 15 September 1949 Nationale Rechte; 1950 DRP, from 20 April 1950 Non-attached)
OTHER
OTHER
Members:
Clausen (from 23 January 1952 FU-Gast, from 3 July 1953 Non-attached)
Ott (Non-attached, from 4 May 1950 WAV-Gast, from 13 October 1950 BHE/DG, from 21 March 1952 Non-attached, from 26 March 1952 DP/DPB-Gast, from 26 June 1952 Non-attached)