The "Cossack era" refers to a period in Eastern European history, particularly in the regions of modern-day Ukraine and Russia, when the Cossacks emerged as a distinct social and military group. This era began in the late 15th century and continued into the 18th century, characterized by the Cossacks' semi-nomadic lifestyle, military prowess, and unique cultural identity. They played a significant role in the defense against invasions and in the expansion of territories. During the Cossack era, the Zaporozhian Cossacks established a democratic form of governance known as the Cossack Hetmanate. This system allowed for elected leaders, or hetmans, to represent the Cossacks' interests. The era was marked by conflicts with neighboring powers, including the Polish-Lithuanian Commonwealth and the Ottoman Empire, as well as internal struggles that shaped the political landscape of Eastern