Though vastly outnumbered and outgunned in what became known as the “Winter War,” the Finns had the advantage of fighting on home turf. Led by Marshal Carl Gustaf Mannerheim, they hunkered down behind a network of trenches, concrete bunkers and field fortifications on the Karelian Isthmus and beat back repeated Soviet tank assaults. Elsewhere on the frontier, Finnish ski troops used the rugged landscape to conduct hit-and-run attacks on isolated Soviet units. Their guerilla tactics were only aided by the freezing Finnish winter, which bogged the Soviets down and made their soldiers easy to spot against snowy terrain. One Finnish sniper, a farmer named Simo Häyhä, was eventually credited with over 500 kills.
