The medieval Church was a dominant force in European society from 476 CE to the 16th century. It shaped beliefs, social structures, and politics through its hierarchy, doctrines, and institutions. The Church's influence extended from the highest levels of power to everyday life. Key concepts include papal supremacy, sacraments, and monasticism. The Church faced challenges like simony and heresy, leading to reforms. Its role in education, art, and social welfare was significant, but corruption and worldliness eventually contributed to the Protestant Reformation.