Eugenio Pacelli was a Roman by birth, and came from a distinguished family with a history of serving the Church. Eugenio’s grandfather, Marcantonio, helped found Vatican newspaper L’Osservatore Romano, his father was dean of the Roman Rota (think: Vatican appeals court), and his brother was a lay canon lawyer and legal advisor to Pius XI. Eugenio’s early career was spent as secretary to Cardinal Gasparri, who codified the 1917 Code of Canon Law, but in 1917 Eugenio was made archbishop and sent as papal nuncio to Germany. From 1929 until his election, he was the Church’s No. 2 as Secretary of State under his mentor, Pius XI.

Pope Pius XII was elected, on his birthday no less, after cardinals supposedly were looking for either a diplomatic or a spiritual candidate. Pius said (probably), “Lucky for you, you're getting both.” His first half-decade as pope was wrapped up with the scourge of Nazism (more on that in a minute), and the rest dealt with the growing threat of Communism. Over the course of his papacy, Pius wrote 41 encyclicals, gave over 1,000 public addresses and radio broadcasts, and (in 1950) proclaimed ex cathedra the Assumption of Mary, infallibly declaring that the Mother of God was assumed body and soul into heaven. Not bad for a guy who had one hand in a perpetual boxing match with Hitler and Stalin for almost 20 years.

Pius spent nearly two decades in the Chair of Peter, but none were more notable than his first six years. It was well-known that Pius fought bitterly against Nazi oppression of the Jews, Poland, and the Church at large -- even before he became pope. In 1935, while still Cardinal Pacelli, he called Nazis, “miserable plagiarists who dress up old errors with new tinsel.” Sugar-coating sold separately.

The trend only continued after he ascended to the papal throne, despite the effects of anti-Catholics to paint an alternate picture of him (something ironically begun by a fictional post-war German play called The Deputy). Pius XII’s Nazi opposition, in fact, has been made crystal clear in just the past few years thanks to declassified U.S. intelligence documents and Mark Riebling’s landmark book, Church of Spies. Not only did Pius actively work to save hundreds of thousands of Jews (you read that right) -- often giving asylum to hordes in his own summer residence -- but he played a clandestinely-active part in a plot to assassinate Hitler. NBD.

Fun Fact: Just seven years after his 1958 death, Pius XII’s cause for canonization was opened by Pope Paul VI. He was declared a Servant of God by St. John Paul II in 1990 and made “Venerable” -- alongside John Paul, in fact -- by Pope Emeritus Benedict XVI in 2009. Pope Francis even said in 2013 that he considered making Pius a saint without the required beatification process, similar to his elevation of John XXIII to sainthood.

In 1955, medical researcher and virologist Dr. Jonas Salk developed the polio vaccine, all but allowing the disease to be prevented in children for the first time ever.