von Güns; died 26/29 September 1274), commonly known as Henry the Great, was a Hungarian influential lord in the second half of the 13th century who was the founder and first member of the powerful Kőszegi family.

Other works present different origin theories, Simon of Kéza's Gesta Hunnorum et Hungarorum writes that the brothers came from "Vildonia", referring to Burgruine Wildon in Styria, however the castle itself was built only after 1157 thus that identification is incorrect.

According to historian Jenő Szűcs, he belonged to Béla IV's accompaniment, who fled Hungary through Transdanubia, escaping from the invading Mongols after the disastrous Battle of Mohi in 1241.

It is possible that the young Henry, whose inherited lands laid in the escape route along the Austrian border, entered court service there and remained a member of the escort in Dalmatia, where Béla and his family took refugee in the well-fortified towns on the coast of the Adriatic Sea.

[7] Receiving large-scale personal land donations for his military career and loyalty in the upcoming decades, he was the founder and first member of the Kőszegi family (formerly incorrectly also called Németújvári or Güssingi in historiography),[8] which had dominated the northwestern part of Vas County and their lands were arranged around significant fortresses, for instance Borostyánkő (today Bernstein in Austria) and the eponymous Kőszeg, which was developed into an advanced trading town under Henry's domination, who granted town privileges to the settlement and moved his permanent residence there after a construction of a well-fortified castle.

With Béla's support and generous donations,[9] Henry Kőszegi established his lordship independently of his kinship and did not rely on the clan's formerly acquired landholdings in the opposite parts of Vas County.

Thus the earlier Hungarian historiographical efforts to call the family as "Németújváris" or "Güssingis" (and also "Küszinis") is unfounded and anachronistic; nevertheless, they are still appear as "Güssingers" in German-language academic works.

[19] Nevertheless, Anna's army occupied the fort of Patak (ruin near Sátoraljaújhely) and captured Stephen's wife, Elizabeth the Cuman and children, including the future Ladislaus IV.

Thereafter, Henry and his troops began to besiege and occupy Stephen's castles one after another in the eastern parts of Upper Hungary, while a small unit recovered Anna's formerly confiscated estates in Bereg County.

[19] After the fall of Patak, Duke Stephen sent his faithful soldier Peter Csák to the northern parts of the junior king's realm, who successfully besieged and regained the fort of Baranka (today ruins in Ukraine) from Henry's troops.

[21] The king-junior's partisans relieved the castle and he started a counter-attack in the autumn against Henry's army in Northern Hungary, who presumably received no news of the defeat of Lawrence's besiegers.

Because of the prolonged siege of Feketehalom (which, in fact, failed by then) Henry Kőszegi sent a skillful military general Ernye Ákos with an army of Cuman warriors to Tiszántúl, in order to support the besiegers and, later, to hinder Duke Stephen's counter-offensive.

Béla of Macsó was able to flee the battlefield, while Henry Kőszegi was taken prisoner by a young courtly knight, Reynold Básztély, who knocked the powerful lord out of the horse's saddle with his lance and captured him on the ground.

However, the mobilized royal servants were not enthusiastic about another internal conflict, instead they demanded the recognition of their rights and privileges from Béla, and the name of the absent duke was included in the charter at their request.

After that, he resided in Vas County and attempted to reconcile his late father's old partisans, including Henry Kőszegi and Lawrence Aba, and appointed royal castellans to the border forts due to the threat of war with Bohemia.

Although his rebellion was crushed within days by late November, Zsoldos argues the revolt and its suppression resulted that, instead of peaceful conciliation, several lords, who possessed lands along the border, including Henry Kőszegi and his sons, Lawrence Aba and Nicholas Geregye, followed Duchess Anna into exile to Bohemia and handed their castles to Ottokar II, who placed the treasonous nobles under his protection.

The raid escalated into war by the spring of 1271, when Ottokar invaded the lands north of the Danube in April 1271 and captured a number of important fortresses in Upper Hungary.

A prominent baron, Egidius Monoszló, laid siege in late August to the Dowager Queen's palace in Székesfehérvár to "rescue" Ladislaus from the rival baronial group's influence, but his action ended in failure as the Gutkeled troops routed his army after some clashes and bloodshed.

Béla of Macsó, who governed the southern provinces of the Kingdom of Hungary, also appeared in the royal court in order to demand more power, direct and respectful influence in the affairs of the realm.

[43] Together with Ladislaus' kidnapping by Joachim Gutkeled a few months earlier, it marked the beginning of a new era in the Kingdom of Hungary, called "feudal anarchy", which lasted until the 1320s and was characterized by the crisis of royal authority, constant struggles for power and the emergence of oligarchic territorial provinces.

The intensity and brutality of the murder is indicated by personal anger that has escalated since the Battle of Isaszeg, when Béla managed to flee the battlefield, leaving behind his lieutenants, including the captured Henry.

[44] During the meeting, Henry accused Béla of treason, who presumably contacted with Ottokar II through his mother Duchess Anna, who was still residing in Prague, to stabilize the domestic political crisis.

[45] Immediately after the assassination, Henry Kőszegi has made an alliance with Joachim Gutkeled and the Geregye brothers, forming one of the two main baronial groups, while the other one was dominated by the Csák and Monoszló clans.

As historian Jenő Szűcs analyzed, the elderly honored barons, who were made palatines and other chief officials during that time, such Denis Péc, Ernye Ákos and Roland Rátót were functioned as stable points and "beauty spot" in the fast-changing governments.

Although, Henry Kőszegi successfully prevented the advance of the Bohemians along the river Vág (Váh), large-scale territories and counties remained under the suzerainty of Ottokar and the war had been brought to an end without truce of peace treaty.

Abolishing the balance of power between the two rivaling groups, the Kőszegis and their allies expelled several members of the royal council and established a homogeneous "party government" in late 1273, as Szűcs called in his monograph.

[3][47] Matthew Csák and his allies removed Voivode Nicholas Geregye from power in early June 1274,[49] but Henry Kőszegi and the Gutkeled brothers were able to retain their positions, although their homogeneous government was terminated.

Fearing the rival group's gradual advancement in the previous weeks, Joachim Gutkeled and Henry Kőszegi captured Ladislaus IV and his mother near Buda at the end of June 1274.

Although Peter Csák liberated the king and his mother in a short time, the two powerful lords, Henry Kőszegi and Joachim Gutkeled captured Ladislaus' younger brother, Andrew, and took him to Slavonia, the centre of their political basis.

Thereafter Peter Csák with the consent of Ladislaus IV gathered an army against the Kőszegis' domain in the autumn of 1274; they marched into Western Hungary, pillaging the brothers' landholdings.