Valuk was a duke of the Slavic duchy of Carantania. After the attempt to capture Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

 in 626 failed, the Avars

Eurasian Avars

The Eurasian Avars or Ancient Avars were a highly organized nomadic confederacy of mixed origins. They were ruled by a khagan, who was surrounded by a tight-knit entourage of nomad warriors, an organization characteristic of Turko-Mongol groups...

 turned towards the west and attacked the territory settled by Slavs. The Slavs then united under their leader Valuk, and joined forces with Samo

Samo

Samo was a Frankish merchant from the "Senonian country" , probably modern Soignies, Belgium or Sens, France. He was the first ruler of the Slavs whose name is known, and established one of the earliest Slav states, a supra-tribal union usually called Samo's empire, realm, kingdom, or tribal...

 (the leader of a Slavic confederation of Czechs, Moravians, Slovaks, and Sorbs) to defend themselves against the Avars. Valuk was possibly the first Duke of Carantania. Carantania was the first Slavic state known to have been created. The capital was located at Karnburg, near Klagenfurt

Klagenfurt

-Name:Carinthia's eminent linguists Primus Lessiak and Eberhard Kranzmayer assumed that the city's name, which literally translates as "ford of lament" or "ford of complaints", had something to do with the superstitious thought that fateful fairies or demons tend to live around treacherous waters...

 in present-day Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

. It is unknown if Valuk's bloodline was continued in that of the later Dukes of Carantania.

Sources