Charlie Eshbach, the guiding force behind the success of the Portland Sea Dogs for the past quarter century, is stepping down as president of the minor league baseball franchise, the team announced Monday.

Charlie Eshbach shakes hands with catcher Matt Spring after a ceremony in 2013 at Hadlock Field to honor Eshbach’s 20 years with the team. Five years later, Eshbach is stepping down.

Eshbach, 66, was the Sea Dogs’ first employee and has been their only president. He was hired by then team owner Dan Burke in October 1992 to oversee building a club that would become the Florida Marlins’ affiliate in the Double-A Eastern League.

The Sea Dogs began play in 1994 and five years later “Baseball America” magazine named them the best operation in minor league baseball. The Sea Dogs have continued to rank annually among the top 25 franchises in minor league baseball in merchandising sales.

“I don’t know if there’s anybody in minor league baseball that has done as much as he’s done and had the success he’s had and that’s not by mistake,” said Sea Dogs general manager Geoff Iacuessa, who was promoted Monday to team president and will continue to serve as the GM.

Eshbach, who lives in Falmouth, will continue his ties to the Sea Dogs as a senior adviser. He said Iacuessa’s duties won’t change much. Iacuessa became the general manager in 2010.

“To be perfectly honest, in the last year or two I’ve been taking steps back anticipating this would happen,” Eshbach said Monday. “I’ve become less hands on with the day-to-day operations. (Iacuessa has) been the point person with the city. He’s done all the hiring and firing and all of that.”

Eshbach’s 45-year career in minor league baseball includes an 11-year stint as president of the Eastern League before joining the Sea Dogs. He was general manager of the Bristol (Connecticut) Red Sox at age 22 and took over as league president at 29.

“Charlie was employee number 1 at the Portland Sea Dogs and the best hire my father could have made,” Sea Dogs team chairman Bill Burke said in a news release. “He has led this franchise with vision and high integrity and his hard work and good humor have been invaluable to all of us.”

Charlie Eshbach posed with a shovel at Hadlock Field on March 23, 2005, to show how much snow remained two weeks before the team’s scheduled home opener.

Bill Burke and his sister Sally McNamara, the team treasurer, are the current owners of the team. Dan Burke, the former CEO of Capital Cities/ABC, died in 2011.

“Charlie’s fingerprints are all over this franchise and none of our success would have been possible without him,” McNamara said in the release.

When Eshbach joined forces with Dan Burke to bring baseball back to Portland for the first time since 1949, they were confident they could build a successful team.

“We came in with a promise. We thought it would do well and the team could succeed and if it did do well we thought it could become an institution in the city and it all happened real quick,” Eshbach said. “We thought we could draw a quarter-million people that first year and we drew 375,000 and it became a much bigger success than we had hoped.”

The Sea Dogs’ connection to New England was strengthened when they began their current affiliation as the Double-A team of the Boston Red Sox in 2003. That switch was facilitated when John Henry, the former Marlins’ owner, became the primary owner of the Red Sox.

“We’re still a hometown team but the fact we’re affiliated with the Red Sox means so much more,” Eshbach said.

Eshbach and the Sea Dogs have earned several honors over the past 25 years. In 2000, Minor League Baseball awarded the Sea Dogs with the John H. Johnson President’s Trophy, presented to the complete baseball franchise for its stability and contributions to the league, its community and the overall baseball industry.

Eshbach was named the Eastern League Executive of the Year in 1978 (while with the Bristol Red Sox), 1994 and 2002. In 2013, he was named “King of Baseball,” Minor League Baseball’s highest honor.

In August, Eshbach was inducted into the Portland Sea Dogs Hall of Fame, along with outfielder Jacoby Ellsbury.

This season the Sea Dogs averaged 5,678 fans for 61 home dates, their best average since 2010 and fourth-best in the 12-team Eastern League. Eshbach said Iacuessa has played a significant part in keeping the Sea Dogs’ brand resonant in the community.

“He took a general manager’s job at a company that had a long history of being successful and not only maintained that success but improved on it,” Eshbach said.

Red Sox president and CEO Sam Kennedy echoed that sentiment in Monday’s release.

“On behalf of John Henry, Tom Werner, all the men and women of the Boston Red Sox, I congratulate Geoff Iacuessa on this well-earned promotion and we look forward to continuing to work with him to develop future Red Sox,” Kennedy said.

The Sea Dogs’ affiliation with the Red Sox runs through the 2020 season. The Professional Baseball Agreement between all major and minor league teams expires at the same time. Iacuessa said until a new PBA is worked out, affiliation deals can’t be extended but he is confident that the Sea Dogs and Red Sox will continue to work together.

“I think it’s incredibly strong, a great working relationship,” Iacuessa said.

The team’s lease at city-owned Hadlock Field runs through 2028, he said.

Iacuessa also has a long tenure with the Sea Dogs. While finishing his degree in sports management at the University of Massachusetts, he did an eight-month internship with the Sea Dogs in 2001.

“My adviser at the time told me, ‘if you get offered one at Portland, take it,’ and he nailed it on the head,” Iacuessa said.

Iacuessa was hired as the director of group sales the next year. He became the assistant general manager after the 2006 season, and the executive vice president and general manager in 2010.

“Geoff possesses all of the personal qualities we could ever want in a team president and has worked hard to earn this promotion,” Bill Burke said.

Iacuessa, 39, who lives in South Portland, was named to the Portland Press Herald’s “40 under 40” list recognizing local business leaders in 2011.

Steve Craig can be reached at 791-6413 or:

scraig@pressherald.com

Twitter: SteveCCraig