Editing Samuel of Bulgaria (section)

===War with Hungary===
{{Main article|Bulgarian–Hungarian wars}}
[[File:First Bulgarian Empire (976-1018).png|right|thumb|300px|Map of Bulgaria in its largest extension during Samuel's reign circa 1000.<ref name=delev/>]]

The Byzantine–Bulgarian conflict reached its apex in 1003, when Hungary became involved. Since the beginning of the 9th century, the Bulgarian territory had stretched beyond the [[Carpathian Mountains]] as far as the [[Tisza]] River and the middle Danube. During the reign of Samuel, the governor of these northwestern parts was duke [[Ahtum]], the grandson of duke [[Glad (duke)|Glad]], who had been defeated by the Hungarians in the 930s. Ahtum commanded a strong army and firmly defended the northwestern borders of the Empire. He also built many churches and monasteries through which he spread Christianity in [[Transylvania]].<ref>''Legenda Saneti Gerhardi episcopi'', p. 489.</ref><ref>Venedikov, p. 150.</ref>

Although Gavril Radomir's marriage to the daughter of the Hungarian ruler had established friendly relations between the two strongest states of the Danube area, the relationship deteriorated after Géza's death. The Bulgarians supported Gyula and Koppány as rulers instead of Géza's son [[Stephen I of Hungary|Stephen I]]. As a result of this conflict, the marriage between Gavril Radomir and the Hungarian princess was dissolved. The Hungarians then attacked Ahtum, who had directly backed the pretenders for the Hungarian crown. Stephen I convinced Hanadin, Ahtum's right-hand man, to help in the attack. When the conspiracy was uncovered Hanadin fled and joined the Hungarian forces.<ref>''Legenda Saneti Gerhardi episcopi'', pp. 492–493.</ref> At the same time, a strong Byzantine army besieged Vidin, Ahtum's seat. Although many soldiers were required to participate in the defense of the town, Ahtum was occupied with the war to the north. After several months he died in battle when his troops were defeated by the Hungarians.<ref>Venedikov, pp. 151–152.</ref>  As a result of the war, Bulgarian influence to the northwest of the Danube diminished.