King of Croatia in the context of "Sigismund I the Old"

Béla III (Hungarian: III. Béla, Croatian: Bela III., Slovak: Belo III.; c. 1148 – 23 April 1196) was King of Hungary and Croatia between 1172 and 1196. He was the second son of King Géza II and Géza's wife, Euphrosyne of Kiev. Around 1161, Géza granted Béla a duchy, which included Croatia, central Dalmatia and possibly Sirmium. In accordance with a peace treaty between his elder brother, Stephen III, who succeeded their father in 1162, and the Byzantine Emperor Manuel I Komnenos, Béla moved to Constantinople in 1163. He was renamed to Alexios, and the emperor granted him the newly created senior court title of despotes. He was betrothed to the Emperor's daughter, Maria. Béla's patrimony caused armed conflicts between the Byzantine Empire and the Kingdom of Hungary between 1164 and 1167, because Stephen III attempted to hinder the Byzantines from taking control of Croatia, Dalmatia and Sirmium. Béla-Alexios, who was designated as Emperor Manuel's heir in 1165, took part in three Byzantine campaigns against Hungary. His betrothal to the emperor's daughter was dissolved after her brother, Alexios, was born in 1169. The emperor deprived Béla of his high title, granting him the inferior rank of kaisar.

Stephen III died on 4 March 1172, and Béla decided to return to Hungary. Before his departure, he pledged that he would never make war against the Byzantine Empire. Although the Hungarian prelates and lords unanimously proclaimed Béla king, Lucas, Archbishop of Esztergom opposed his coronation because of Béla's alleged simony. Finally, the Archbishop of Kalocsa crowned him king on 18 January 1173, with Pope Alexander III's approval. Béla fought with his younger brother, Géza, whom he held in captivity for more than a decade. Taking advantage of the internal conflicts in the Byzantine Empire after Emperor Manuel's death, Béla reoccupied Croatia, Dalmatia and Sirmium between 1180 and 1181. He occupied the Principality of Halych in 1188, but it was lost within two years.

Louis I, also known as Louis the Great (Hungarian: Nagy Lajos; Croatian: Ludovik Veliki; Slovak: Ľudovít Veľký) or Louis the Hungarian (Polish: Ludwik Węgierski; 5 March 1326 – 10 September 1382), was King of Hungary and Croatia from 1342 and King of Poland from 1370 until his death in 1382. He was the first child of Charles I of Hungary and his wife, Elizabeth of Poland, to survive infancy. A 1338 treaty between his father and Casimir III of Poland, Louis's maternal uncle, confirmed Louis's right to inherit the Kingdom of Poland if his uncle died without a son. In exchange, Louis was obliged to assist his uncle to reoccupy the lands that Poland had lost in previous decades. He bore the title Duke of Transylvania between 1339 and 1342 but did not administer the province.

Louis was of age when he succeeded his father in 1342, but his deeply religious mother exerted a powerful influence on him. He inherited a centralized kingdom and a rich treasury from his father. During the first years of his reign, Louis launched a crusade against the Lithuanians and restored royal power in Croatia; his troops defeated a Tatar army, expanding his authority towards the Black Sea. When his brother, Andrew, Duke of Calabria, husband of Queen Joanna I of Naples, was assassinated in 1345, Louis accused the queen of his murder and punishing her became the principal goal of his foreign policy. He launched two campaigns to the Kingdom of Naples between 1347 and 1350. His troops occupied large territories on both occasions, and Louis adopted the styles of Neapolitan sovereigns (including the title of King of Sicily and Jerusalem), but the Holy See never recognized his claim. Louis's arbitrary acts and atrocities committed by his mercenaries made his rule unpopular in Southern Italy. He withdrew all his troops from the Kingdom of Naples in 1351.

Béla IV (1206 – 3 May 1270) was King of Hungary and Croatia between 1235 and 1270, and Duke of Styria from 1254 to 1258. As the oldest son of King Andrew II, he was crowned upon the initiative of a group of influential noblemen in his father's lifetime in 1214. His father, who strongly opposed Béla's coronation, refused to give him a province to rule until 1220. In this year, Béla was appointed Duke of Slavonia, also with jurisdiction in Croatia and Dalmatia. Around the same time, Béla married Maria, a daughter of Theodore I Laskaris, Emperor of Nicaea. From 1226, he governed Transylvania as duke. He supported Christian missions among the pagan Cumans who dwelled in the plains to the east of his province. Some Cuman chieftains acknowledged his suzerainty and he adopted the title of King of Cumania in 1233. King Andrew died on 21 September 1235 and Béla succeeded him. He attempted to restore royal authority, which had diminished under his father. For this purpose, he revised his predecessors' land grants and reclaimed former royal estates, causing discontent among the noblemen and the prelates.

The Mongols invaded Hungary and annihilated Béla's army in the Battle of Mohi on 11 April 1241. He escaped from the battlefield, but a Mongol detachment chased him from town to town as far as Trogir on the coast of the Adriatic Sea. Although he survived the invasion, the Mongols devastated the country before their unexpected withdrawal in March 1242. Béla introduced radical reforms in order to prepare his kingdom for a second Mongol invasion. He allowed the barons and the prelates to erect stone fortresses and to set up their private armed forces. He promoted the development of fortified towns. During his reign, thousands of colonists arrived from the Holy Roman Empire, Poland and other neighboring regions to settle in the depopulated lands. Béla's efforts to rebuild his devastated country won him the epithet of "second founder of the state" (Hungarian: második honalapító).

Tomislav (pronounced [tǒmislaʋ], Latin: Tamisclaus) was the first king of Croatia. He became Duke of Croatia c. 910 and was crowned king by 925, reigning until c. 928. During Tomislav's rule, Croatia forged an alliance with the Byzantine Empire against Bulgaria. Croatia's struggles with the First Bulgarian Empire eventually led to war, which culminated in the decisive Battle of the Bosnian Highlands in 926. In the north, Croatia often clashed with the Principality of Hungary; the state retained its borders and, to some extent, expanded with the disintegrated Lower Pannonia.

Tomislav attended the 925 Council of Split, convened by Pope John X, to discuss the use of Slavic languages in liturgy, and ecclesiastical jurisdiction over both Croatia and the Byzantine Theme of Dalmatia. Although the Pope sought to prohibit Slavic liturgy, the council did not agree. Jurisdiction over the region was given to the Archbishop of Split instead of Bishop Gregory of Nin. Since historical information on Tomislav is scarce, the exact years of his accession and death are unknown. The reigns of his successors were marked by a series of civil wars in Croatia and a gradual weakening of the country.

Géza II (Hungarian: II. Géza; Croatian: Gejza II.; Slovak: Gejza II.; 1130 – 31 May 1162) was King of Hungary and Croatia from 1141 to 1162. He was the oldest son of Béla the Blind and his wife, Helena of Serbia. When his father died, Géza was still a child and he started ruling under the guardianship of his mother and her brother, Beloš. A pretender to the throne, Boris Kalamanos, who had already claimed Hungary during Béla the Blind's reign, temporarily captured Pressburg (now Bratislava in Slovakia) with the assistance of German mercenaries in early 1146. In retaliation, Géza who came of age in the same year, invaded Austria and routed Henry Jasomirgott, Margrave of Austria, in the Battle of the Fischa.

Although the German–Hungarian relations remained tense, no major confrontations occurred when the German crusaders marched through Hungary in June 1147. Two months later, Louis VII of France and his crusaders arrived, along with Boris Kalamanos who attempted to take advantage of the crusade to return to Hungary. Louis VII refused to extradite Boris to Géza, but prevented the pretender from contacting his supporters in Hungary and managed to shepherd him to Constantinople with the rest of the crusaders. Géza joined the coalition that Louis VII and Roger II of Sicily formed against Conrad III of Germany and Byzantine emperor Manuel I Komnenos.

Stephen III (Hungarian: III. István, Croatian: Stjepan III.; Slovak: Štefan III.; summer of 1147 – 4 March 1172) was King of Hungary and Croatia between 1162 and 1172. He was crowned king in early June 1162, shortly after the death of his father, Géza II. However, his two uncles, Ladislaus and Stephen, who had joined the court of the Byzantine Empire, challenged his right to the crown. Only six weeks after his coronation, the Byzantine Emperor Manuel I Komnenos launched an expedition against Hungary, forcing the Hungarian lords to accept Ladislaus' rule. Stephen sought refuge in Austria, but returned and seized Pressburg (now Bratislava in Slovakia). Ladislaus, who died on 14 January 1163, was succeeded by Stephen's younger uncle and namesake, Stephen IV, without resistance, but his rule was unpopular. The young Stephen defeated his uncle on 19 June 1163 and expelled him from Hungary.

Stephen IV attempted to regain his throne with Emperor Manuel I's support, but the latter made peace with Stephen III. He agreed to send his younger brother, Béla, to Constantinople and to allow the Byzantines to seize Béla's duchy, which included Croatia, Dalmatia and Sirmium. In an attempt to recapture these territories, Stephen III waged wars against the Byzantine Empire between 1164 and 1167, but could not defeat the Byzantines.

Andrew II (Hungarian: II. András, Croatian: Andrija II., Slovak: Ondrej II., Ukrainian: Андрій II; c. 1177 – 21 September 1235), also known as Andrew of Jerusalem, was King of Hungary and Croatia between 1205 and 1235. He ruled the Principality of Halych from 1188 until 1189/1190, and again between 1208/1209 and 1210. He was the younger son of Béla III of Hungary, who entrusted him with the administration of the newly conquered Principality of Halych in 1188. Andrew's rule was unpopular, and the boyars (or noblemen) expelled him. Béla III willed property and money to Andrew, obliging him to lead a crusade to the Holy Land. Instead, Andrew forced his elder brother, King Emeric of Hungary, to cede Croatia and Dalmatia as an appanage to him in 1197. The following year, Andrew occupied Hum.

Although Andrew did not stop conspiring against Emeric, the dying king made Andrew guardian of his son, Ladislaus III, in 1204. After the premature death of Ladislaus, Andrew ascended the throne in 1205. According to historian László Kontler, "[i]t was amidst the socio-political turmoil during [Andrew's] reign that the relations, arrangements, institutional framework and social categories that arose under Stephen I, started to disintegrate in the higher echelons of society" in Hungary. Andrew introduced a new grants policy, the so-called "new institutions", giving away money and royal estates to his partisans despite the loss of royal revenues. He was the first Hungarian monarch to adopt the title of "King of Halych and Lodomeria". He waged at least a dozen wars to seize the two Rus' principalities, but was repelled by the local boyars and neighboring princes. He participated in the Fifth Crusade to the Holy Land in 1217–1218, but the crusade was a failure.

Ladislaus I (Hungarian: I. László, Croatian: Ladislav I., Slovak: Ladislav I., Polish: Władysław I; c. 1040 – 29 July 1095), also known as Saint Ladislas, was King of Hungary from 1077 and King of Croatia from 1091. He was the second son of King Béla I of Hungary and Richeza (or Adelaide) of Poland. After Béla's death in 1063, Ladislaus and his elder brother, Géza, acknowledged their cousin Solomon as the lawful king in exchange for receiving their father's former duchy, which included one-third of the kingdom. They cooperated with Solomon for the next decade. Ladislaus's most popular legend, which narrates his fight with a "Cuman" (a Turkic nomad marauder) who abducted a Hungarian girl, is connected to this period. The brothers' relationship with Solomon deteriorated in the early 1070s, and they rebelled against him. Géza was proclaimed king in 1074, but Solomon maintained control of the western regions of his kingdom. During Géza's reign, Ladislaus was his brother's most influential adviser.

Géza died in 1077, and his supporters made Ladislaus king. Solomon resisted Ladislaus with assistance from King Henry IV of Germany. Ladislaus supported Henry IV's opponents during the Investiture Controversy. In 1081, Solomon abdicated and acknowledged Ladislaus's reign, but he conspired to regain the royal crown, and Ladislaus imprisoned him. Ladislaus canonized the first Hungarian saints (including his distant relatives, King Stephen I and Duke Emeric) in 1085. He set Solomon free during the canonization ceremony.

Coloman the Learned, also the Book-Lover or the Bookish (Hungarian: Könyves Kálmán; Croatian: Koloman; Slovak: Koloman Učený; c. 1070 – 3 February 1116), was King of Hungary from 1095 and King of Croatia from 1097 until his death. Because Coloman and his younger brother Álmos were underage when their father Géza I died, their uncle Ladislaus I ascended the throne in 1077. Ladislaus prepared Coloman—who was "half-blind and humpbacked", according to late medieval Hungarian chronicles—for a church career, and Coloman was eventually appointed bishop of Eger or Várad (Oradea, Romania) in the early 1090s. The dying King Ladislaus preferred Álmos to Coloman when nominating his heir in early 1095. Coloman fled from Hungary but returned around 19 July 1095 when his uncle died. He was crowned in early 1096; the circumstances of his accession to the throne are unknown. He granted the Hungarian Duchy—one-third of the Kingdom of Hungary—to Álmos.

In the year of Coloman's coronation, at least five large groups of crusaders arrived in Hungary on their way to the Holy Land. He annihilated the bands who were entering his kingdom unauthorized or pillaging the countryside, but the main crusader army crossed Hungary without incident. He invaded Croatia in 1097, defeating its last native king Petar Snačić. Consequently, he was crowned king of Croatia in 1102. According to the late 14th-century Pacta conventa (the authenticity of which is not universally accepted by scholars), he was only crowned after having ratified a treaty with the leaders of the Croatian nobility. For centuries thereafter, the Hungarian monarchs were also the kings of Croatia.