Sixers coach Brett Brown showed his players video on Monday morning of previous encounters between these two franchises, which have included battles between Wilt Chamberlain and Bill Russell, and Larry Bird and Julius Erving.
"Before we even got into X's and O's and scout tape, look at the history here," Brown said of his message to the Sixers. "Have a real kind of knowledge base of our two organizations. It's something historic, it's something very special. ... [The] series we're all about to play in, and compete in, there's a lot that's gone on long before us that's worth knowing about."
In the 1960s, Chamberlain and Philadelphia faced off against Russell and the Celtics. Erving's Sixers and Bird's Celitcs battled in the 1980s.
"There's a deep history between the two teams. Really two of the most storied franchises in NBA history," veteran Philadelphia guard JJ Redick said Sunday. "It's obviously an honor to play in that rivalry."
The Sixers and Celtics have met 19 times in the playoffs; Boston has won 12 of those series. Sixers star Joel Embiid studied the rivalry on his own during Philadelphia's five-day break between the first and second rounds. The most memorable moment?
"Dr. J and Larry Bird holding each other's necks," Embiid said, referencing the fight between Bird and Erving during a regular-season game early in the 1984-85 season.
Embiid said Erving's message in the video on Monday morning referenced the intensity of the Celtics-Sixers rivalry. "These are the type of moments I live for, so I'm excited," Embiid said.
This will be just the third playoff series between Boston and Philadelphia in the past 32 years.
The Sixers have a talented young core led by Embiid, 24, and 21-year-old point guard Ben Simmons. The Celtics have their own young core, featuring Kyrie Irving, top rookie Jayson Tatum -- who was selected with a pick acquired in a trade with Philadelphia -- young wing Jaylen Brown and guard/forward Gordon Hayward.
The Celtics, however, are on this playoff run without their star, Irving, who had season-ending knee surgery in April, and new acquisition Hayward, who was lost for the season to an ankle injury in the first game.
Given the young talent, Embiid believes that this can be the first of several playoff meetings between the two franchises.
"I think that when you look at the whole league and you talk about the future of the league, we're up there. They're up there," he said. "So it's going to be fun the next couple of years."