Must watch fights for an aspiring boxing historian?

That's a bit harsh. The IBRO quarterly journals are far better than any magazine out there today. The way to become a historian is to read and learn, and by joining the IBRO you'll get a very fast start.

As far as historians go, no one knows it all. Most of them specialize in a period of boxing or a geographic region of boxing history.

Collectively they add to the forgotten history of the sport.

 

Don’t forget to read as much as you can about the sport and it’s history

 

Welcome to the club, OP.

Watch the collected career of Harry Greb first. (That’s a joke, Greb is an all-timer yet no film of him fighting exists ... or at least none has been discovered and made known publicly, it’s the great white whale of boxing history.)

Seriously, I invite you to explore the light heavyweight division of the 1970s — perhaps the best collection of talent in one division ever, or at least certainly in my lifetime. Among them:

Matthew Saad Muhammad (Matt Franklin before he took up Islam and changed his name)
Marvin Johnson
Eddie Mustafa Muhammad (formerly Eddie Gregory)
James Scott (became a top contender while fighting in prison, great story and fun guy to watch)
Michael Spinks
Dwight Muhammad Qawi (formerly Dwight Braxton)
Victor Galindez
Yaqui Lopez
John Conteh
Mike Rossman

There are others, but you’ll find several fights between the above so there was a lot of mixing and matching and little avoidance (other than Scott being unable to obtain a title shot due to his circumstances being imprisoned, although he did knock off top contenders).

You should also explore the Four Kings (plus one):
Sugar Ray Leonard
Thomas Hearns
Marvin Hagler
Roberto Duran
(Plus Wilfred Benitez)
Again, plenty of cross-pollination among them fighting each other.

I’d also suggest you read, among other books, The Sweet Science by A.J. Liebling, a collection of essays on boxing by a great writer who wrote extensively on the sport from Ray Robinson to early Cassius Clay (later to be known as Muhammad Ali). You’ll learn a lot about the game’s colorful characters.

Enjoy the ride.