Born in Vienna, he was the second but eldest surviving son[citation needed] of Sigismund II, Count of Dietrichstein and Baron of Hollenburg, Finkenstein and Thalberg, by his second wife Johanna von der Leiter (della Scala), Baroness (Freiin) von der Leytter zu Behrn und Vicenz, heiress of Amerang and member of the Scaliger family, former rulers of Verona.

In his youth he was at the service of Archduke Matthias of Austria and closely watched the growing disputes between him and his unpopular older brother, Emperor Rudolph II.

A few days later (23 May) took place the Defenestration of Prague, where (primarily thanks to the intervention of his uncle, Cardinal Franz Seraph of Dietrichstein, Prince-Bishop and Duke of Olomouc), Maximilian managed to avoid the involvement of his Moravian estates in the following uprising.

Ten years later, on 7 August 1629, Maximilian received, according to the law of primogeniture, the title of Imperial Count Palatine (Kaiserliche Hofpfalzgraf) with unlimited territorial competence.

Thanks to the special intercession of Emperor Ferdinand III, Maximilian received a seat and vote in the Reichstag at Regensburg, with the condition of the acquisition of a direct imperial territory.

Thanks to the Fideikommiss granted by his uncle Franz Seraph, Maximilian was able to purchase the Lordships of Kanitz, Wostitz (Vlasatice), Saar (Žďár nad Sázavou) and Steinabrunn (in the district of Korneuburg in Lower Austria), where he instituted the primogeniture.