Yaromir the Determined

 
The double eagle banner began with Yaromir Lantsov, or Yaromir the Determined, who was the first King of Ravka and the originator of its monarchy. The world into which Yaromir was born was one rife with conflict, even more so than during the Border Wars. Before Yaromir, Ravka was not a nation so much as an assortment of regions who could never be at peace; but, demonstrative of the determination in his name, Yaromir did not rest until he had united them all as one. Under his reign, an alliance was established with warrior monks who helped to protect Ravka, and conflicts with Fjerda and Shu Han were also put to rest, for a time.
Quotes from the Series
 
Yuri hesitated, then said, “It begins with the first Lantsov king, Yaromir the Determined.” He shut his eyes, his voice taking on a more confident, even cadence. “Before him, the territory that would become Ravka was little more than a collection of warring provinces led by squabbling kings. He subdued them and brought them together beneath his double-eagle banner. But the invasions from Fjerda to the north and Shu Han to the south were relentless and put the young kingdom in a constant state of war.” [...] “There was no Second Army then,” Yuri continued. “Ravka’s soldiers fought and died just as other men did. But as the legend goes, Yaromir built an altar atop a hill in Os Alta—” “The site of the first royal chapel,” said Tolya. Yuri nodded. “The young king prayed to all of the Saints who would hear him, and the next day, a group of monks arrived at his door and offered to fight by his side. [...] The monks plunged into battle and sent the enemies of Ravka scattering, pushing them back and forming the borders that would hold, more or less, for thousands of years. [...] Those who survived became men once more and their leader took his place beside Yaromir. Eventually, the priest who held the office closest to the king was given the title of Apparat, and the holy soldiers that surrounded him became the Priestguard.”
King of Scars by Leigh Bardugo, p.130–131
 
Prepared by Kaishi Yul-Khaan
World of the Grishaverse ©