History has a funny way of flattening things out. When you look back at the list of popes 20th century, it’s easy to imagine a line of solemn men in white robes just sort of... existing. But honestly? It was absolute chaos. Between 1900 and 1999, the papacy went from being a "prisoner" of the Vatican to a global media powerhouse that helped topple empires. We’re talking about nine men who had to navigate two world wars, the rise of communism, the sexual revolution, and the invention of the internet. It wasn’t just about theology; it was about survival.
Most people think the Vatican is this unchanging monolith. It isn't. The 1900s forced the Church to decide if it was going to hide behind its walls or finally join the modern world. Some of these guys were traditionalists who hated change. Others were radicals. And a few were just trying to keep the lights on while Europe burned around them.
From Leo to Pius: The Old Guard Faces the Great War
The century kicked off with Leo XIII, but he’s basically a 19th-century hangover who died in 1903. The real story begins with Pius X.
Pius X was... intense. If you like the Latin Mass and old-school rules, he’s your guy. He hated "Modernism" with a passion. He actually made priests take an oath against it. He was a peasant by birth, which was a huge deal at the time, and he famously hated the pomp of the papal court. But then came 1914. They say the heartbreak of World War I starting is what actually killed him. He died just weeks after the guns began firing.
Then you’ve got Benedict XV. Poor guy. He’s basically the "Forgotten Pope" because he spent his entire reign (1914–1922) trying to stop the carnage of WWI. He stayed neutral, which made everyone mad. The Allies thought he was pro-German; the Germans thought he was pro-Allies. He basically emptied the Vatican’s bank accounts to provide food and medical aid to refugees. He was a diplomat in a world that had forgotten how to talk.
Pius XI took over in 1922, and he’s the one who finally fixed the "Roman Question." See, for decades, the popes refused to leave the Vatican because they were mad at the Italian government. Pius XI signed the Lateran Treaty in 1929 with Mussolini. Yeah, that Mussolini. It’s a complicated legacy. He created Vatican City as a sovereign state, but it meant playing ball with a dictator. Toward the end of his life, though, he became a fierce critic of Hitler and racism, even commissioning an encyclical against Nazism that was released just as he died.
The Massive Shadow of Pius XII
You can't talk about the list of popes 20th century without hitting the biggest controversy of the bunch: Pius XII.
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Eugenio Pacelli. He was the Pope during World War II. People still argue about him today. Was he "Hitler’s Pope," as some critics claim, or was he a silent hero who saved thousands of Jews by hiding them in monasteries and even at his summer residence, Castel Gandolfo? It’s probably both and neither. He was a diplomat by training. He believed that if he spoke out too loudly, the Nazis would retaliate by killing even more Catholics and Jews in occupied territories. He chose "silence" over public condemnation, a decision that haunts the Church’s reputation to this day.
Regardless of where you land on the ethics of his silence, Pius XII was the last of the truly "imperial" popes. He was regal. He was distant. He was the end of an era. When he died in 1958, everyone expected a "caretaker" pope—someone old who wouldn't do much.
They got John XXIII.
The "Good Pope" Who Broke Everything
John XXIII was supposed to be a placeholder. He was 76, chubby, and incredibly friendly. Everyone loved him. Then, he decided to call the Second Vatican Council (Vatican II), and the Church basically exploded.
Vatican II changed everything:
- Mass stopped being said in Latin (mostly).
- The priest turned around to face the people.
- The Church stopped blaming Jewish people for the death of Jesus.
- It started talking about religious freedom as a human right.
He didn't live to see it finish. He died in 1963, leaving the mess—and the glory—to Paul VI.
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Paul VI and the Identity Crisis
Paul VI is the pope people forget, but he had the hardest job. He had to finish the Council and then figure out how to implement it without the whole Church splitting in half.
He was an intellectual. He was tortured by his decisions. He’s the one who wrote Humanae Vitae in 1968, the document that reaffirmed the ban on artificial birth control. This was a massive turning point. It’s where a lot of lay Catholics basically said, "Thanks, but no thanks," and started making their own decisions about their private lives. He saw the Church through the 1960s and 70s, which were objectively wild years for the Vatican.
The Year of Three Popes
1978 was a weird year. Paul VI died in August. The cardinals elected John Paul I, "The Smiling Pope." He lasted 33 days.
33 days!
There are conspiracy theories, of course. Some say he was murdered because he wanted to clean up the Vatican Bank. Most historians agree he likely had a heart attack because the job was just too much for his health. His death led to the second conclave of 1978, and that’s when everything changed.
The Super-Pope: John Paul II
Karol Wojtyła. The first non-Italian pope in 455 years. A Pole. An actor. A philosopher. A survivor of both Nazism and Communism.
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If the list of popes 20th century had a celebrity superstar, it was him. He reigned for 26 years, taking us right through the end of the century and into the next. He was a walking contradiction. He was a rockstar who could fill stadiums, but he was also a hardline conservative on things like women’s ordination and liberation theology.
He played a massive role in the fall of the Iron Curtain. By visiting Poland and supporting the Solidarity movement, he gave people the moral courage to stand up to the Soviet Union. He was shot in 1981, survived, and then went to the prison to forgive his assassin.
But his legacy is also tied to the beginning of the clerical sex abuse scandal coming to light. While he was traveling the world and kissing the ground in every country he visited, the institution he led was beginning to face a reckoning that would define the next century.
Understanding this list isn't just about memorizing names. It’s about seeing how the world shifted. We went from Pius X’s fear of "modernity" to John Paul II using satellite TV to reach billions. The Church entered 1900 as a grumpy old man shouting at the world to get off its lawn; it finished the century as a complex, often troubled, but undeniably global force.
How to Actually Use This History
If you're researching this for a project or just because you’re a history nerd, don't just look at the dates. Look at the "why."
- Check the Sources: If you want the real grit, read Saints and Sinners: A History of the Popes by Eamon Duffy. It’s the gold standard for a reason—it doesn't sugarcoat the politics.
- Visit the Archives: The Vatican recently opened the archives for the pontificate of Pius XII. If you're into original research, that’s where the current "hot" history is happening.
- Trace the Maps: Look at a map of Europe in 1914 versus 1999. The papacy had to adapt to those borders changing in real-time. It explains why they were so obsessed with diplomacy.
- Watch the Footage: We have actual video of every pope from Pius XI onwards. Seeing John XXIII’s "Moonlight Speech" or John Paul II in Poland gives you a vibe that text just can't.
The 20th century was a meat grinder for every institution, and the papacy was no exception. It’s a story of men trying to hold onto 2,000 years of tradition while the world around them was moving at the speed of light. Whether you’re a believer or a skeptic, you’ve got to admit: it was a hell of a run.