Answer: Pope Pius X died of a heart attack in 1914. He was beatified in 1951 and canonized a saint in 1954. Thus, he became the first 20th century Pope to be canonized. He is also the first Pope to be canonized a saint since the 17th century.

See also:
 •  Anonymous Beatification Of Pope Pius X Vatican Notes Volume 6 Issue 4, Page 3
  • William Wonneberger, Jr., Canonization Of Pope Pius X Vatican Notes Volume 07, Issue 2 1958 Page 8


Pope Pius X Beatification
Scott # 145-148 (1951)


Pope Pius X Canonization
Scott # 182-184 (1954)