linguistic:voice_change, linguistic:paraphrasing, structural:expansion
Consolidation (1001– c. 1009)

Although Stephen's power did not rely on his coronation, the ceremony granted him the internationally accepted legitimacy of a Christian monarch who ruled his realm " by the Grace of God ". All his legends testify that he established an archbishopric with its see in Esztergom shortly after his coronation. This act ensured that the Church in Hungary became independent of the prelates of the Holy Roman Empire. The earliest reference to an archbishop of Esztergom, named Domokos, has been preserved in the deed of foundation of the Pannonhalma Archabbey from 1002. According to historian Gábor Thoroczkay, Stephen also established the Diocese of Kalocsa in 1001. Stephen invited foreign priests to Hungary to evangelize his kingdom. Associates of the late Adalbert of Prague, including Radla and Astrik, arrived in Hungary in the first years of his reign. The presence of an unnamed "Archbishop of the Hungarians" at the synod of 1007 of Frankfurt and the consecration of an altar in Bamberg in 1012 by Archbishop Astrik show that Stephen's prelates maintained a good relationship with the clergy of the Holy Roman Empire.

The transformation of Hungary into a Christian state was one of Stephen's principal concerns throughout his reign. Although the Hungarians' conversion had already begun in his father's reign, it was only Stephen who systematically forced his subjects to give up their pagan rituals. His legislative activity was closely connected with Christianity. For example, his First Book of Laws from the first years of his reign includes several provisions prescribing the observance of feast days and the confession before death. His other laws protected property rights and the interests of widows and orphans, or regulated the status of serfs.

If someone has such a hardened heart—God forbid it to any Christian—that he does not want to confess his faults according to the counsel of a priest, he shall lie without any divine service and alms like an infidel. If his relatives and neighbors fail to summon the priest, and therefore he should die unconfessed, prayers and alms should be offered, but his relatives shall wash away their negligence by fasting in accordance with the judgement of the priests. Those who die a sudden death shall be buried with all ecclesiastical honor; for divine judgment is hidden from us and unknown.

Many Hungarian lords refused to accept Stephen's suzerainty even after his coronation. The new King first turned against his own uncle, Gyula the Younger, whose realm "was most wide and rich", according to the Illuminated Chronicle. Stephen invaded Transylvania and seized Gyula and his family around 1002 or in 1003. The contemporary Annals of Hildesheim adds that Stephen converted his uncle's "country to the Christian faith by force" after its conquest. Accordingly, historians date the establishment of the Diocese of Transylvania to this period. If the identification, proposed by Kristó, Györffy and other Hungarian historians, of Gyula with one Prokui — who was Stephen's uncle according to Thietmar of Merseburg — is valid, Gyula later escaped from captivity and fled to Bolesław I the Brave, Duke of Poland (r. 992–1025).

territory included a certain burg, located near the border with the Hungarians. Its guardian was lord Prokui, an uncle of the Hungarian king. Both in the past and more recently, Prokui had been driven from his lands by the king and his wife had been taken captive. When he was unable to free her, his nephew arranged for her unconditional release, even though he was Prokui's enemy. I have never heard of anyone who showed such restraint towards a defeated foe. Because of this, God repeatedly granted him victory, not only in the burg mentioned above, but in others as well.

About a hundred years later, the chronicler Gallus Anonymus also made mention of armed conflicts between Stephen and Boleslav, stating that the latter "defeated the Hungarians in battle and made himself master of all their lands as far as the Danube ". Györffy says that the chronicler's report refers to the occupation of the valley of the river Morava — a tributary of the Danube — by the Poles in the 1010s. On the other hand, the Polish-Hungarian Chronicle states that the Polish duke occupied large territories north of the Danube and east of the Morava as far as Esztergom in the early 11th century. According to Steinhübel, the latter source proves that a significant part of the lands that now form Slovakia were under Polish rule between 1002 and 1030. In contrast with the Slovak historian, Györffy writes that this late chronicle "in which one absurdity follows another" contradicts all facts known from 11th-century sources.

The Illuminated Chronicle narrates that Stephen "led his army against Kean, Duke of the Bulgarians and Slavs whose lands are by their natural position most strongly fortified" following the occupation of Gyula's country. According to a number of historians, including Zoltán Lenkey and Gábor Thoroczkay, Kean was the head of a small state located in the southern parts of Transylvania and Stephen occupied his country around 1003. Other historians, including Györffy, say that the chronicle's report preserved the memory of Stephen's campaign against Bulgaria in the late 1010s.

Likewise, the identification of the " Black Hungarians " — who were mentioned by Bruno of Querfurt and Adémar de Chabannes among the opponents of Stephen's proselytizing policy — is uncertain. Györffy locates their lands to the east of the river Tisza; while Thoroczkay says they live in the southern parts of Transdanubia. Bruno of Querfurt's report of the Black Hungarians' conversion by force suggests that Stephen conquered their lands at the latest in 1009 when "the first mission of Saint Peter" — a papal legate, Cardinal Azo — arrived in Hungary. The latter attended the meeting in Győr where the royal charter determining the borders of the newly established Bishopric of Pécs was issued on 23 August 1009.

The Diocese of Eger was also set up around 1009. According to Thoroczkay, "it is very probable" that the bishopric's establishment was connected with the conversion of the Kabars — an ethnic group of Khazar origin — and their chieftain. The head of the Kabars — who was either Samuel Aba or his father — married Stephen's unnamed younger sister on this occasion. The Aba clan was the most powerful among the native families who joined Stephen and supported him in his efforts to establish a Christian monarchy. The reports by Anonymus, Simon of Kéza and other Hungarian chroniclers of the Bár-Kalán, Csák and other 13th-century noble families descending from Hungarian chieftains suggest that other native families were also involved in the process.

Stephen set up a territory-based administrative system, establishing counties. Each county, headed by a royal official known as a count or ispán, was an administrative unit organized around a royal fortress. Most fortresses were earthworks in this period, but the castles at Esztergom, Székesfehérvár and Veszprém were built of stone. Forts serving as county seats also became the nuclei of Church organization. The settlements developing around them, where markets were held on each Sunday, were important local economic centers.