The significance of the Reformation on the Catholic Church was monumental, leading to profound ecclesiastical and societal changes. Initiated by figures like Martin Luther, the movement challenged the Church's practices and doctrines, resulting in the fragmentation of Western Christianity and the establishment of various Protestant denominations. In response to the Reformation, the Catholic Church undertook the Counter-Reformation, implementing reforms to address corruption and reaffirm core beliefs. This period reshaped religious landscapes across Europe, influencing politics, culture, and education, and fostering a sense of individual religious interpretation.