Pope Saint Pius X (1835–1914), revered for his pastoral care and unwavering commitment to Catholic tradition, dedicated his papacy to combating modernism, which he saw as a grave threat to the Church’s teachings. Through key documents like the encyclical Pascendi Dominici Gregis (1907), he condemned modernist interpretations and required clergy to take an oath against these errors, safeguarding theological orthodoxy. Celebrated as the "Pope of the Eucharist" for promoting frequent communion and lowering the age for first communion, Pius X's legacy endures through the efforts of groups like the Third Order of the Society of Saint Pius X, who continue his mission by preserving traditional Catholic values and teachings. His feast day stands as a testament to his role as a steadfast defender of the faith against the intellectual challenges of his time.