For the better part of two years, documentary filmmaker Jon Dunham has been looking for a deep-pocketed benefactor that could help make his documentary about the Boston Marathon a reality.

Finally, Dunham has found his big sponsor, a name familiar to anyone who has run the race: John Hancock Financial.

The Boston-based life insurer plans to announce on Thursday that it has agreed to be the title sponsor of "Boston." Boston Athletic Association officials say this will be the first feature-length documentary film about the marathon's rich history.

The bombings and their aftermath will certainly play a key role, but the film will also take a broader look at the nearly 120-year-old race.


John Hancock, of course, already has a long history with Boston's premier race: The company helped rescue the event from financial trouble roughly 30 years ago and has remained its principle sponsor.

Executives at John Hancock, now a part of Manulife Financial Corp., aren't saying how much they're spending on the movie sponsorship contract with Dunham's firm, LA Roma Films. Before John Hancock signed on, Dunham said he had raised about $1 million of the $2 million he needs from a group of investors.

"Not only will it tell an interesting story about the marathon, but I think it will talk about our community in ways that will help us all reflect on it," said Jim Gallagher, executive vice president at John Hancock. "It's not just a film for runners. It's a bigger story than that. It's really about Boston and our community."

Dunham is well known to the running community for his earlier work, namely two "Spirit of the Marathon" documentaries.

He said his interest in making this film predates the 2013 marathon bombings: He first reached out to the Boston Athletic Association, the race's organizer, earlier that year. The attacks that marred the race helped seal Dunham's interest in capturing the event.


Dunham, who will direct the movie, said he found it tough to line up financial support in Boston. Only one of the movie's 10 investors so far — unofficial marathon historian Tom Derderian — is from this area, Dunham said.

To some extent, Dunham attributed the initial difficulty to competition with the Boston 2024 Olympics effort.

"We were told . . . that the Boston Marathon film was an interesting project, but there were at least one or two individuals that declined to ultimately get involved because they were too dedicated to the Olympic effort," Dunham said.

But like a dedicated marathoner, Dunham kept plowing ahead. His race for funds outlasted Boston 2024's. Now, with nearly 80 percent of the shooting done and John Hancock's financial backing assured, Dunham said he's excited for the next chapter. Dunham is based in Italy, but his business partner, Megan Williams, is in the Los Angeles area, and the film will most likely be edited there.

Boston Athletic Association executive director Tom Grilk said his group offered Dunham access to the organization's archives and helped connect him with other information sources and race sponsors. Grilk said Dunham's movie-making skill was already well known in the running community because of his work on his two "Spirit of the Marathon" films.

At least now Dunham sounds confident that he has a timeline in place for the movie's release, in late 2016.


"It's a real vote of confidence to have a company that's as large and as well established as John Hancock to be the sponsor," Dunham said.

Jon Chesto can be reached at jon.chesto@globe.com. Follow him on Twitter @jonchesto.