Signed as an unrestricted free agent, he was coming to Boston as its captain, a new era of Bruins hockey in his sights.
"That was the changing moment for the Boston Bruins," former teammate Torey Krug said. "He changed the culture. He changed the standards."
He changed the fortunes of the Bruins, stung eight months earlier by the trade of Joe Thornton to the San Jose Sharks, and ushered in a period when Boston would win the Stanley Cup once, in 2011 with a seven-game victory against the Vancouver Canucks, and go to the Cup Final two more times, in 2013 and 2019.
And now, with the decision by the Bruins not to re-sign him and the news Wednesday that the 43-year-old agreed to a one-year, $795,000 contract with the Washington Capitals, that era is over.
"He gave the Bruins the identity that they've been playing with for the last 14 years he was there," former defense partner Dennis Seidenberg said. "And he was part of that culture change that he brought with him when [former general manager Peter] Chiarelli signed him to that first contract with the Bruins and ever since I think they didn't look back."
It wasn't Chara alone, of course. Mark Recchi was there. Patrice Bergeron. The heart and soul were spread among a group of leaders that carried the Bruins forward. But the driving, propelling force always was Chara.
"He set the bar in so many different ways, as far as work ethic, leadership, commitment, communication, empathy, you name it," said Shawn Thornton, a forward who played with Chara in Boston for seven seasons from 2007-14. "You had to give it everything you had, just to keep up to the pace he was pushing in all those different areas."
He was the first on the ice and often the last off it.
He was the one who was the Bruins' pullup champion in fitness testing as recently as 2017, when he was 40 years old, besting players half his age.
He scored 481 points (148 goals, 333 assists) in 1,023 games over 14 seasons with Boston, part of a 22-season career in which he has so far scored 656 points (205 goals, 451 assists) in 1,553 games for the Bruins, Ottawa Senators and New York Islanders while being one of the best shutdown defensemen of all time.
Video: Zdeno Chara joins Washington Capitals
Chara won the Norris Trophy voted as the best defenseman in the NHL in 2008-09. He has excelled on the penalty kill and at the end of games, his long stick a menace.
And for the Bruins, he was, in so many ways, the barometer.
"He's the ultimate measuring stick for the Boston Bruins, and why he's pushed so many guys around him to greatness as well," said Krug, who signed with the St. Louis Blues on Oct. 9 after playing 523 games for the Bruins in nine seasons from 2011-20. "People are always trying to outwork Zdeno, and it doesn't happen. When people are trying to, that means they're reaching their potential, and that's what forces greatness on other people."
He formed a partnership with Bergeron, an alternate captain and his likely successor, a player who shared his drive and his ability to inspire. They asked for a lot from their teammates, but it didn't create resentment. It didn't chafe. As Seidenberg said, "I loved it. I loved the challenge."
Before the shortened 2012-13 NHL season, the Bruins were skating at Boston College in December, as they waited and hoped for a resolution that would allow them to get back to playing hockey. Chara had been playing in the Kontinental Hockey League for HC Lev Praha, in Prague, Czech Republic, but had returned for Christmas.
"We're skating at BC at 8 in the morning, every single day, basically," Shawn Thornton said. "It's December something, he comes back for Christmas from playing in the KHL, takes a 15-hour flight back overnight. I think he came right to the rink and was yelling at us to get on the ice on time at 8:15. That's how he's wired."
The Bruins made it to Game 6 of the Stanley Cup Final that season, losing to the Chicago Blackhawks.
He did not take a day off. And so his teammates did not take days off.
"You had to be able to look the big man in the eyes," Shawn Thornton said.
So it's difficult to overstate Chara's impact on the Bruins.
"It's hard to put it into words," said defenseman Charlie McAvoy, Chara's partner for the past three seasons. "He's just done everything for me, from the moment I got here to now, just helping me grow so much as a player and a person. And just the way he carries himself."
McAvoy said he was thankful to have played with Chara, grateful. That was the message from many of Chara's former teammates -- he changed the trajectory of the organization, of their own careers, he tutored young defensemen and molded them, as he had molded himself from an ungainly 6-foot-9 defenseman into a likely Hockey Hall of Famer.
He changed the Bruins. He changed them as individuals.
"There's only a handful of players, probably, that are that dominant on the ice and create culture, that command the best out of the organization," Shawn Thornton said. "I mean, I know he loves TB12 (longtime New England Patriots quarterback Tom Brady). And he's been compared to him a lot as a hockey player. I think it's actually fair, like coaches can yell at you, coaches can expect the best of you, GMs can expect the best of you, but until you create a culture within the room, that the players believe in the leadership and the culture they've bought into, that's when you have true success. And Zee, Bergeron, those guys definitely have created that in that locker room."
It made them all lucky, to play with him, to be motivated by him, to be steered by him. As Seidenberg said, his teammates were lucky. The city of Boston was lucky. Now, it seems, the city of Washington will be lucky. Because there's just something about Chara.
"It's an 'it' factor," Shawn Thornton said. "There's a number of star players that don't have 'it,' right? Like that just go out and shoot pucks and score goals, but they're not changing the culture of an organization. Zee helped change the culture of that organization."