John Thavis finds himself at a rare moment in history. A journalist and author who has written about the Vatican for nearly 30 years, Thavis arrived in Rome just hours before Pope Benedict’s unexpected resignation.

“I’m just amazed,” the Minnesota native said during a phone interview this week from Rome, where he served as bureau chief for the U.S.-based Catholic News Service before retiring nearly a year ago. He returned to Rome to promote his new book, “The Vatican Diaries.”

“When I walked into the press office, all my old colleagues looked at me and said, ‘You knew.’ But I didn’t really.”

Since Benedict’s announcement that he will step down Feb. 28, Thavis, 62, has emerged as a key Vatican expert. His book, a behind-the-scenes account of the personalities and politics of Vatican life, went on sale Thursday and is getting an unexpected boost from the pope’s news.

“My publisher is very happy about the timing,” Thavis dryly quipped.

While Thavis said he was shocked by Benedict’s announcement, he had seen indications that the 85-year-old pontiff might be stepping back.

“He did not have too many big events on his calendar. Practically none for 2013. And he had just named six new cardinals, which seemed to me he was topping off the College of Cardinals before a conclave [meeting of cardinals to choose a new pope].”

“So in a sense I was thinking this would be a good time for me to come [to Rome]. If he did resign, I would at least be here. And that’s the way it worked out.”

Born in Mankato, Thavis attended Catholic schools growing up and graduated from St. John’s University in 1973. With a background in classical languages, he traveled to Italy four years later and worked as a writer and editor at the Rome Daily American before returning in 1979 to Minnesota. There he worked at the Mankato Free Press until 1982, when he and his wife, Lauren, decided to move to Rome.

During his nearly three decades with the Catholic News Service, Thavis traveled with Pope John Paul II and Benedict to more than 60 countries. In his book, Thavis said he sought to shed light on the inner workings of the Vatican, which mystifies many people.

“I was convinced the way the Vatican seemed to outsiders and the news media is a caricature of the place ... and that many of the most interesting things I witnessed were things I had never written about because they don’t fit into news stories.

“The perception is it’s a very hierarchical structure and very controlled environment where everything happens according to script. And you don’t have to be here too long before you realize that’s absolutely not true.

“In actual fact, it is often kind of minor characters, the bit players, who end up having a huge impact on events, not necessarily the top cardinals.”

Thavis says he plans to stay in Rome until the new pope is chosen. Then he has speaking engagements in Minnesota in April and May. In June, he and his wife plan to move to St. Paul, where Thavis wants to continue writing.

As for the next pope, Thavis says he can’t predict who it will be, though it’s likely to be someone who shares Benedict’s conservative leanings and vision for the church.

“I do think the choice of the pope will have an impact on people and how they view the Catholic Church,” Thavis said. “The pope is a very visible figure, all around the world.”