The Leonardopoulos–Gargalidis coup d'état attempt was a significant moment in Greek history, marked by an effort to overturn the republican government instituted after the tumultuous Greco-Turkish War. The conspiracy involved Colonel Konstantinos Leonardopoulos and Major General Spyridon Gargalidis, both staunch royalists who believed that a coup was necessary to re-establish the monarchy that had been ousted during a period of political upheaval. On the designated day, the conspirators mobilized loyal troops and attempted to seize key locations in Athens, aiming to rally support among military and civil leaders loyal to King George II, who had fled Greece years earlier.The republican government, however, was prepared for such a scenario. Upon learning of the royalists' plans, government forces acted quickly to defend their positions. Armed confrontations erupted, and the coup was swiftly quelled. In the aftermath, the government arrested the conspirators, leading to increased public disdain for the monarchy. The failed coup demonstrated the fragility of royal power in Greece and ultimately discredited the institution of monarchy. The political landscape transformed significantly, progressively leading to the establishment of the Second Hellenic Republic, a major shift in the governance of Greece that favored republican ideals over monarchical rule.