Back in his days at Owings Mills High School, Jack Gilden participated in a program sponsored by the then-Baltimore Colts in which student journalists were paired with professional writers to talk shop.

Jack Gilden

Jack Gilden’s new book, “Collision of Wills,” chronicles the rivalry between Johnny Unitas and Don Shula, two seminal figures in NFL history. (Handout photo)

Gilden was editor of the school’s newspaper in the early 1980s, and something that John Steadman mentioned in conversation stuck in his mind. The veteran Baltimore Sun and News-American sportswriter told him that the Colts’ legendary quarterback Johnny Unitas despised the team’s head coach, Don Shula.

It was a statement that Gilden, now 53, never forgot.

“I guess I was about 15 or 16,” he said. “I said to myself, ‘That would make a great book.’ It was just something that stuck with me.”

Eventually, Steadman’s observation led to Gilden writing his debut book, “Collision of Wills: Johnny Unitas, Don Shula, and the Rise of the Modern NFL” (University of Nebraska Press). To be released in October, the 352-page book focuses on the occasionally tempestuous relationship between Unitas and Shula when the latter coached the Colts from 1963 to 1969.

The quarterback and coach clashed frequently, especially about the team’s offense, which Unitas viewed as his area of expertise. The Colts never won a championship during that period. They were one of the best teams in the NFL during that time, but lost in the 1964 NFL title game — before there was a Super Bowl — and then lost Super Bowl III four years later (although Unitas missed most of that season due to an arm injury).

“Overall, when I got the book, I was just immediately taken by the quality of the writing and all the information that has never been told before,” said Emily Williamson, Gilden’s literary agent. “I could tell right away this guy really knew his stuff. It tells a good story, too. It’s not just your typical sports story.”

A Towson resident, Gilden began to put the book together with guidance from Unitas’ daughter, Jan, whom he already knew.

Unitas died in September of 2002 at age 69, but Shula lives in Indian Creek, Fla. Gilden interviewed him, other former Colts and others during the six years of working on the book.

Gilden said he learned a lot after talking for a few hours with Shula, now 88. Unitas and Shula actually were teammates on the Colts during the 1950s, and the quarterback might have had difficulty accepting that the former defensive back was now his coach, Gilden said.

“[Shula said he] came back to the Colts and Unitas looked at me like I was still a [bad] player, and he was the biggest star in the game,” Gilden said. “Shula said that he was always trying to catch up with Unitas. It was an adversarial relationship – they disliked each other.”

Both wanted control and to help guide the team, Gilden said, but in retrospect Shula admitted he could have forged a better relationship with Unitas.

“He talked about how high-strung he was and how he did not handle things the way that he had wished he had,” Gilden said. “Shula was candid about that.”

Said former Colts halfback Tom Matte: “The one thing that Shula really wanted was people to cooperate. But [Shula and Unitas] still made it work together because he was still the head coach. A couple of times, Unitas said, ‘You just take care of the defense and I’ll take care of the offense.’ But we had the cooperation of the coaching staff [which helped].”

Writing “Collision of Wills” proved to be an evolving process for Gilden. He said he began numerous drafts before finally finding one that satisfied him.

What may have also made the project particularly challenging is that Gilden was aware of how popular the Colts were in Baltimore during the 1960s. In fact, they may have been the NFL team most popular in their own city at that time. Sundays were always reserved for football in Baltimore during the season, and Gilden wanted the book to capture that mood and those memories.

“All of the men of my father’s generation revered the Colts and loved them,” he said. “I loved the Colts.”

A veteran freelance writer and father of two, Gilden worked in the advertising field for many years and ran his own firm in Baltimore. He said working on this book helped him personally in many ways.

“I feel really reinvigorated as a person,” Gilden said. “It’s really exciting to me to do so much research and delve into something so deeply, and figure out how to make a compelling narrative out of that. I really loved that.”

When initially working on the book, Gilden said he wondered why Unitas and Shula — both members of the Pro Football Hall of Fame — could not simply get along. After all, Shula won more games than any coach in NFL history, while many still contend that Unitas was the game’s greatest quarterback.

“There was no real answer,” Gilden concluded. “The closest thing to it was they fought about play-calling, but I think in general there were just many areas of irritation between these two men. That was just the way it was. They had lots and lots and lots of irritation points between them.”

Jeff Seidel is a Baltimore-based freelance writer.