Question: Before 21 Lithuanian dukes signed a peace treaty with Galicia–Volhynia, what is an example of the war-related functions the group who made up the majority of the military-economic staff of the state performed?

<P0-S0> Dausprungas (also "Dovsprunk" in Russian sources, died before 1238) was the older brother of Mindaugas, the first King of Lithuania. <P0-S1>  Dausprungas is mentioned in the peace treaty with Galicia–Volhynia in 1219 among the 21 early dukes of Lithuania as one of the five elder dukes, the other four being Živinbudas, Daujotas, Mindaugas and Viligaila (Daujotas' brother). <P0-S2>  Since Dausprungas is the only known brother of Mindaugas, Mindaugas' nephews Edivydas and Tautvilas are presumed to be his sons. <P0-S3>  If that is true, then Dausprungas is father-in-law of Daniel of Halych and he was also married to Vykintas' sister. <P0-S4>  Because it is known that Mindaugas used to kill his relatives to gain power and because Dausprungas is not mentioned in any other sources, some imply that he was killed by Mindaugas, but others rebut since his sons still ruled their lands in 1248. <SEP> <P1-S0> The history of Lithuania between 1219 and 1295 concerns the establishment and early history of the first Lithuanian state, the Grand Duchy of Lithuania. <P1-S1>  From this point on the history of Lithuania is recorded in chronicles, treaties, and other written documents. <P1-S2>  In 1219, 21 Lithuanian dukes signed a peace treaty with Galicia–Volhynia. <P1-S3>  The beginning of the 13th century marks the end of the prehistory of Lithuania. <P1-S4>  This event is widely accepted as the first proof that the Baltic tribes were uniting and consolidating. <P1-S5>  Despite continuous warfare with two Christian orders, the Livonian Order and the Teutonic Knights, the Grand Duchy of Lithuania was established and gained some control over the lands of Black Ruthenia, Polatsk, Minsk, and other territories east of modern-day Lithuania that had become weak and vulnerable after the collapse of Kievan Rus'. <SEP> <P2-S0> Galicia–Volhynia Wars were several wars fought in the years 1340–1392 over the succession in the Principality of Galicia–Volhynia (in modern Poland and Ukraine). <P2-S1>  After Boleslaw-Yuri II was poisoned by local nobles in 1340, both Grand Duchy of Lithuania and Kingdom of Poland advanced claims over the principality. <P2-S2>  After a prolonged conflict, Galicia–Volhynia was divided between Poland (Galicia) and Lithuania (Volhynia) and the principality ceased to exist as an independent state. <P2-S3>  Poland acquired a territory of approximately 52000 km2 with 200,000 inhabitants. <SEP> <P3-S0> Leičiai (singular: leitis) were a distinct social group of the Lithuanian society in the early Grand Duchy of Lithuania subordinate to the Lithuanian ruler or the state itself. <P3-S1>  Leičiai made up the majority of the military-economic staff of the state: they enforced state authority in the periphery, protected state borders, and performed various other war-related functions, such as breeding riding horses. <P3-S2>  By the 15th and 16th centuries, leičiai were in decline, already losing some of their functions and prestige, and they disappeared as a social class after the implementation of the Wallach Reform. <P3-S3>  Leičiai were native to the Lietuva Land and formed the core of the Lithuanian society in the pre-state era and during the establishment of the state.