[2][3] Matthias played a significant role in the familial opposition of the Habsburgs against his brother Emperor Rudolf II.

[4] Matthias was born in the Austrian capital of Vienna as the fourth son of Maximilian II, Holy Roman Emperor and of Maria of Spain.

Matthias had come into contact with Gautier van der Gracht, the envoy of the Dutch provinces, at the Regensburg Reichstag in 1576.

His work is noted in Article 13 of the 1579 Union of Utrecht, which established freedom of religion as a locally determined issue.

[8] Matthias continued as titular governor for the rebels until their deposing of Philip II and declaration of full independence in 1581, when he returned home to Austria.

It was only after his brother Ernest was appointed General Governor in the Netherlands in 1593, where he ruled from 1594, that Matthias secured governance over Austria.

Matthias initially avoided an argument with the emperor, but Bishop Klesl urged him to take command in the Brothers' Quarrel with Rudolf.

[10][15] As unrest resurfaced in Hungary and spread into parts of Moravia and Austria, Matthias attempted to use the opposition in the power struggle against the emperor.

Although he could not fully win over the Bohemian estates, he forced Rudolf to negotiate and to sign a peace treaty in June 1608, which unsurprisingly resulted in the redistribution of power.

The emperor's wife founded the Capuchin Church and the Imperial Crypt in Vienna as the future burial site of the Habsburg family.

Matthias had already been forced to grant religious concessions to Protestants in Austria and Moravia, as well as in Hungary, when he had allied with them against Rudolf.

Matthias imprisoned Georg Keglević, the Commander-in-chief, General, Vice-Ban of Croatia, Slavonia and Dalmatia and since 1602 baron in Transylvania, but soon freed again.

The Principality of Transylvania was a fully-autonomous area of Hungary but under the nominal suzerainty of the Ottoman Empire, where it was the time of the Sultanate of Women.

The Protestant Bohemians were concerned about their religious freedom and so fiercely opposed all Catholic officials who were appointed by Matthias, particularly Archduke Ferdinand, who was elected King of Bohemia in June 1617.

The dispute came to a head in the Bohemian Protestant revolt, which provoked Matthias to imprison Klesl and to revise his policies.

; Archduke of Austria, Duke of Burgundy, Brabant, Styria, Carinthia, Carniola, Margrave of Moravia, Duke of Luxemburg, of the Upper and Lower Silesia, of Württemberg and Teck, Prince of Swabia, Prince of Transylvania, Count of Habsburg, Tyrol, Kyburg and Gorizia, Landgrave of Alsace, Marquess of the Holy Roman Empire, Burgovia, the Enns, the Upper and Lower Lusatia, Lord of the Marquisate of Slavonia, of Port Naon and Salines, etc.