Bulcsú (or Vérbulcsú; Latin: Bultzus, Greek: Βουλοσουδης "Boulosoudes" and Βουλτζους "Boultzous", Arabic: Wulǧūdī; c. 910 – 15 August 955) was a Hungarian chieftain and military leader in the 10th century.

[32] István Herényi considered that Bulcsú ruled over all subjugated people (e.g. Khavars, Székelys, Pechenegs and Kylfings) of the Hungarian tribal federation holding the title of harka, which could originally have been the gyula's deputy or sub-leader.

[33] Dániel Bácsatyai compared the harka with the dignity tudun of the Avar Khaganate, arguing Bulcsú perhaps governed the western portions of the principality in the name of the grand prince.

[38][39] Ferenc Makk claimed that Bulcsú's tribe initially settled down in the region between the rivers Maros (Mureș) and Körös, and they were forced to move to Transdanubia, north of Lake Balaton after the Battle of Lechfeld by Grand Prince Taksony.

[43][44][45] In contrast to Bálint Hóman, Bácsatyai rejected the concept of conscious campaign organization by Bulcsú arguing that the Hungarians improvised in France after Otto unexpectedly repulsed their attack.

Bulcsú and the other chieftains, possibly under the command of Gyula II, attacked Fraxinet, then arrived in Catalonia, plundering the region, before entering the northern territories of the caliphate in mid-June 942.

[48] It is also possible that Bulcsú participated in that military campaign in 947, when Taksony and his army marched southwards on the Eastern shore of Italy, reaching Otranto and plundering Apulia for three months.

[63] The 19th-century historians still thought that the parts of the De Administrando Imperio about the Hungarians were compiled from mainly Khazar, Pecheneg and Byzantine reports, refusing the role of Termacsu and Bulcsú's delegation in this context.

Based on the linguistic examinations of Zoltán Gombocz and Géza Fehér in the early 20th century, this belief gradually withered away and the Hungarian diplomatic missions to the Byzantine Empire (948, 952) became the primary sources of information.

Ádám Bollók and János B. Szabó returned to the 19th-century mainstream arguing that two Hungarian chieftains were responsible only the information of Árpád's descendants which Constantine's work preserved.

[68] John Zonaras, who, among others, extracted Skylitzes' chronicle, also mentions that – merging the two legations occurred in 948 and 952 – Bulcsú and Gyula II "came to the emperor, and both of them partook of the divine bath of rebirth, and were initiated into the sacred mysteries of our religion".

[71] Constantine was able to demonstrate the transcendence of the Byzantine Empire (long and bright ceremonies, rich gifts, awarding titles, emperor as godfather), which could have meant the hope that the impressed guest would embrace the (at least nominal) acceptance of Byzantium's supremacy.

Dániel Bácsatyai considered that for Bulcsú, the baptism served, in addition to the immediate acquisition of wealth, that he was in a difficult situation and perhaps wanted to overcome his internal opponents (perhaps Gyula II) with Byzantine political support.

There were subsequent skirmishes between Hungarians and Germans along the river Enns (the natural border between the two entities) in 949 and 950, which resulted that Henry I led an army into Western Hungary in 950 or 951, plundering the region and taking captives, this phenomenon occurred for the first time since the Battle of Pressburg (907).

To avoid direct confrontation with Otto's army, Bulcsú managed his light cavalry to Franconia, where they plundered the estates of Ernst, Count of Sualafeld (otherwise, a lord who supported Liudolf's rebellion), taking about a thousand civilian prisoners.

In early July, the monarch received Hungarian legates, who claimed to come in peace, but who the Germans suspected were actually assessing the outcome of the rebellion, as Widukind narrates.

[88] Gyula Kristó considered that the Hungarians wanted to take advantage of the German domestic political turmoil as soon as possible, before it finally subsided and Otto stabilized his power.

[88] According to Gerhard of Augsburg, who wrote the hagiography of Bishop Ulrich, the Hungarian invaders "devastated the land of Noricum (i.e. Bavaria) from the Danube to the Black Forest, which goes to the mountainous regions".

In early August, Bulcsú ordered the gathering of Hungarian raiding units in Lechfeld at the walls of Augsburg, because he decided to besiege the episcopal city with the siege engines he brought with him.

As a result, Otto sent Conrad the Red and his fourth legion (the Franks) rearwards, who successfully liberated the captives, recovered the loot and drove away the marauding Hungarian units.

The Bohemian auxiliary army commanded by Boleslaus I, Duke of Bohemia clashed with a large fleeing group of the Hungarians in the eastern part of Lechfeld on 11 August, where Lehel and Súr were captured near the fort of Ebersberg.

[21][97] Johannes Aventinus narrates that the prisoners were handed over to "Eberhard, leaders of the Bavarians, who then sent the king [Bulcsú] and the four princes [Lehel, Súr, Taksony and Csaba] to Duke Henry of Bavaria in Regensburg.

[94] Györffy argued the execution of Bulcsú and Lehel caused a psychological shock in Hungary; in accordance with the Hungarian mythology, the three leaders became servants of the Germans in the afterlife, and since they were buried ingloriously and without a sign, they meant misfortune to the living.

[12] By the end of the 10th century, the territory of Somogy and Zala counties in Southern Transdanubia was ruled by Koppány, a member of the Árpád dynasty, who laid claim to the Hungarian throne against Grand Prince Stephen in 997.

Ferenc Makk argued that Taksony, who became Grand Prince after the disastrous Battle of Lechfeld (and thus Aventinus wrongly claimed that he was executed in 955 too), invaded and conquered the territory of Bulcsú's tribe sometime between 955 and 958.

[102] Attila Zsoldos argued that Zerind the Bald was granted the territory by Grand Prince Géza (Stephen's father) as a compensation for which he and his descendants were excluded from power, disregarding the principle of seniority.

Its last known male member was litteratus Pál Ládi (or Miketinci), who lived in the early 16th century, and possessed lands in Balaton-mellék and Slavonia until he died without an heir.

Despite this, his cult in Hungarian historiography only developed in the 20th-century Interwar Hungary through Bálint Hóman, who wrote the medieval period of the high impact monograph series Magyar történet (1928).

The historian considered that Bulcsú is a symbol of that two-decade search for a way from the Battle of Riade (933) to the final defeat at Lechfeld (955), when the main sources of income (ransoms, tributes and booty) for Hungarians began to disappear, and this made the decisive test of strength inevitable between Hungary and Western Europe.

Padányi's essay was utilized by the far-right Neopaganist movement in Hungary after the end of Communism, for instance the picture album Bulcsu (2008) written by Tamás Kubínyi and Sándor Pörzse.