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. 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. 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. 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.