B. Pius IX, pope

Blessed Pius IX, born Giovanni Maria Mastai-Ferretti, was the longest-reigning pope in modern history, serving from 1846 until his death in 1878. He was born on May 13, 1792, in Senigallia, Italy, and is venerated for his unwavering defense of the Church's teachings and his role in the First Vatican Council, which defined the doctrine of papal infallibility. Pius IX is also remembered for his efforts to promote devotion to the Immaculate Conception of the Blessed Virgin Mary and his beatification in 2000 by Pope John Paul II.