Longevity and loyalty seem to sell for so little in the NFL these days, Jerry Seinfeld once jokingly reduced football to a match-up of "our city's jersey against another city's jersey." He was right to a point: players often stayed with one team for a long time, if not their entire career. Coaches were no different: Giants coach Steve Owen was on board for 22 years, same with George Halas, Bill Walsh, and a host of others.
This all didn't change much until free agency was implemented and now the turn-over rate of players moving from team to team is an every season occurrence.
Which is why I believe New York Giants tightends coach Mike Pope deserves a special mention here. Flipping through all my Giants Yearbooks, I realized his picture was a constant. I never thought to read much into his bio, but Mike Pope has been with the Giants for nearly 20 years, on two separate occasions. In fact, he is the only coach to have been with the Giants for all 4 of their Super Bowl trips. Along the way, his coached and mentored 4 great Giants tightends:Zeke Mowatt, Mark Bavaro, Howard Cross, and Jeremy Shockey. Kevin Boss, his current pupil, may be himself on the way to greatness as he has improved his contributions since joining the G-Men in 07. (Incidentally, all 5 of the tightends that Pope has coached have been part of the Giants Super Bowl seasons, with each TE contributing in all of them).
There is a nice bio about Pope in the Giants 2009 Yearbook. He came with the Giants when Parcells was named coach in 1983 and stayed until 1991. In 2000, Pope was asked to come back by Jim Fassel and was then the only coached retained in 2004 when Tom Coughlin became HC.