go back a long way

go back a long way (with sb) (to know someone for a long time) — знать кого-л. очень давно, быть давно знакомым с кем-л.; не первый год друг друга знать || иметь давнюю историю, уходить (корнями) глубоко в прошлое

Example 1: Doris and I go back a long way – we were at school together. — Я сто лет Дорис знаю, мы в одной школе учились.

Example 2: We go back a long way. You know you can count on me. We're blood brothers, right?

Example 3: Louise and Sam were neighbours as children and go back a long way.

Example 4: He and I go back a long way. Have a lot of superficial things in common. Same age, same background. But we're about as different in our personalities and attitudes as two people can be. Me — I've always been a loner. A dreamer. The Steppenwolf type. He, on the other hand, lusted after the limelight and being a celebrity. (H G Stratmann, "Tempora Mutantur", 1999)

Example 5: Jonas and Flynn went back a long way. They'd gone through the FBI Academy together. Jonas had stayed with the Bureau. (Heather Graham, "Deadly night", 2008)

Example 6: "It seems a little silly to an outsider, but their rivalry goes back a long way." "Yes," said O Daugherty. "A very long way, I'm thinking."
(Michael F. Flynn, "Flame of Iron", 1999)

opp.
а nodding / passing acquaintance