In May 1478 he commanded the cottars of the mortgaged Hungarian villages Kismarton and Fraknó – of which he was the captain of, and in which he had spawned the Ordership – to drudge-work in the fortification labour of the city.

At the Ungarthore (English: Hungarian gate) stood the ducal castle with high walls and four stone towers.

After the siege of Vienna King Matthias urged his troops to encircle Wiener Neustadt, which could pose a possible threat to the conquered lands in later times.

He sent captains Stephen Zápolya, Ladislaus Kanizsay, Jakob Székely, Wilhelm Tettauer und Stephan Báthory to begin the siege in 1486.

The drawbridge collapsed, causing many people falling into the trenches where they drowned, others were killed by Hungarians, who advanced to the gates of the city.

Matthias on the other hand reached the moat in front of the Wienerthore (English: Viennese gate) and moved his heavy guns forward, including six enormous ones previously captured from the Ottomans, and brought siege machines that were made to fill the trenches and called for transport pinnaces to serve as mobile bridges.

[6] So the garrison of Wiener Neustadt lacked tall buildings to install the long-range firearms, they mounted them to the bell towers of the churches.

Despite being a devoted Christian Matthias allowed the shelling of the churches except in case of high risk to conflagrate the town with it.

[3] After seven months with several break-in, dig-in, and treachery attempts the city deputies came to the royal camp requesting the cessation of hostilities.

[8] Frederick agreed in a status quo because he was already busy with the Brugge Revolt in Flanders, in which his son Maximilian I was kept hostage by the citizens and his personal presence was needed to solve the situation.

[9][10] In the negotiation Matthias was represented by his Austrian sympathizer counts Christoph von Liechtenstein-Nikolsburg and Leopold Brantz.

Simultaneously Matthias reconquered the cities of Kismarton (Eisenstadt) and Fraknó (Forchtenstein), which in contrast Frederick – as bestow ruler assigned in Peace Treaty of Wiener Neustadt in 1463 – immediately gifted to the Order of Saint George to spark tensions.

Siebenhirter on the other hand on 13 February 1488 waived his right to the villages and subsequently was granted the towns of Trautmannsdorf and Wartenstein in exchange by Matthias.