 Complete the following phrase:  Herbord Osl grew up in the royal court of Andrew II together with Duke Béla, therefore possibly he was born in the early 1200s. He belonged to the group of so-called royal youth , , who supported the monarchs and took a leading role in royal military campaigns. He was first chronologically mentioned by contemporary documents in 1230, when participated in the military campaign of the duke, who crossed the Carpathian Mountains and laid siege to Halych together with his Cuman allies. According to King Bélas charter from 1248, he fought appreciatively at the Porta Rusica lit. Russian Gate, then participated in the skirmish along the river Dniester. It is possible that he also fought in the post-1235 wars against the Kingdom of GaliciaVolhynia, following Béla IV asenceded the Hungarian throne after his fathers death. During the 