Martin Luther (1483–1546) was a seminal figure in the Protestant Reformation that swept across Europe in the 16th century. A theologian, university professor, and Augustinian monk, Luther's writings and actions irrevocably altered the landscape of Christianity and Western religious thought. Born in Eisleben, Saxony, in what is today Germany, Luther initially intended to study law but turned to divinity and entered a monastery after a life-altering thunderstorm incident. Having become increasingly disenchanted with the Catholic Church's teachings and practices, notably the sale of indulgences, Luther penned the 'Ninety-five Theses' in 1517 which he famously nailed to the door of the Wittenberg Castle Church. This act is commonly celebrated as the beginning of the Reformation. One of Luther's crucial works, 'Address To the Christian Nobility of the German Nation' (1520), laid out a compelling critique of the Church's ecclesiastical structures and promoted the idea of a 'priesthood of all believers.' It significantly contributed to the shift in how church authority and scripture were perceived, particularly the claim that laypersons have as much spiritual power as the clergy. Luther's translation of the Bible into German democratized religious texts, making them accessible to the general populace and thereby shaping the German language itself. Luther's legacy extends beyond his written work; his teachings influenced the development of Protestantism in numerous strands and had lasting implications for religion, politics, and society.