In September, during the German occupation of Greece, the Wehrmacht commenced a three-day retaliatory operation against multiple villages in the Viannos region. This oppressive military action was in direct response to the increasing resistance movements in the area, particularly the activities of local partisans who had been conducting sabotage against German forces. Germany's brutal tactics aimed to deter further resistance and instill fear in the local population. The villages targeted included Seli, Ano Viannos, and the surrounding areas, which were viewed as hotbeds of opposition to German rule.

The Wehrmacht's operations included mass executions, arson, and the destruction of property, leaving a deep scar on the local populace. Additionally, the use of collective punishment was part of an overarching strategy that the Nazis employed across occupied territories to suppress dissent. Among the estimated death toll, many victims were non-combatants, including women and children, highlighting the indiscriminate nature of the violence.

The event has been documented as part of the larger narrative of World War II in Greece, showcasing how the German military not only fought against armed resistance but also sought to punish communities that opposed their occupation. The tragic outcomes from these operations contributed to a legacy of suffering and remembrance that continues in Greek history, as survivors have shared their accounts through oral history and literature.