Collinson spends about an hour each day planning, curating, and posting tweets. The preparation for major events—like the German invasion of the Soviet Union, the attack on Pearl Harbor, and D-Day—can take as long as 10 hours. It helps that World War II is one of the most well-studied and documented events in human history; Collinson has at his disposal countless books, newspaper archives, historical records, and other sources. In addition to tweeting the basics, like military operations, Collinson shares quotes from firsthand accounts gleaned from letters and diaries.

“In many ways, it’s like trying to report on the news but years and years ago,” he said. “I’m not just trying to get a sense of who invaded who, which cities fell when, but more of what people thought and how they were trying to make a narrative out of it at the time.”

Collinson was inspired to retrace World War II after watching the events of the Arab Spring play out across social-media platforms in late 2010. Back then, for perhaps the first time, people were using digital means like Twitter and other websites to announce, coordinate, and document widespread political demonstrations in multiple countries. Social media elevated and carried the protests over international borders, reaching anyone with a Twitter handle. The internet made the far-flung events of the movement into something “real and tangible and immediate,” Collinson said.

“I remember being really profoundly moved by the way that you could see history unfolding,” he said. “We didn’t know necessarily how things were going to turn out.”

As @RealTimeWWII’s following grew, users began to reach out to share personal stories, letters, or diaries of family members who lived through the war. Some helpfully corrected Collinson when he tweeted something incorrect, like the wrong name for a military tank in a picture. ( “One of the wonderful advantages of the internet is that people can correct you almost immediately,” he said with a laugh.) Then there were the vitriolic comments. In response to tweets about the Holocaust, Collinson said,“I had neo-Nazis saying, why are you reporting on this Jew news? Get back to real news.”

For the most part, Collinson is tweeting the same kind of content today as he did when he started in 2011. But the atmosphere—of Twitter, of the internet in general—feels different to him. In the last decade, it seems like the discourse on social media has gotten increasingly ugly.

“I suppose now it seems like a less innocent landscape,” Collinson said. “The internet and social media are no longer an escape. It’s just one more way of reflecting, perhaps even in a more disconcerting way, the world that we live in.”

These days, Twitter users are finding more parallels between the events of World War II and current political and economic affairs, particularly in the rise of nationalist sentiment in the United States and Europe. Some people react to the tweets with warnings or lamentations that the world is regressing to early-20th-century ideologies. “Obviously there were terrible events going on [in 2011] as there are terrible events going on now,” Collinson said. “But there was less talk of there being Nazis on the streets of the Western world.”