grammar - A younger generation of men follow or follows?

Could you explain to me which is correct?

1. A younger generation of men follow . . .


2. A younger generation of men follows . . .

Could you also explain why?

I was thinking that the bit that cannot be removed should be the one that determines whether the verb is singular or plural. The sentence would lose its sense without younger generation so does that mean that that is the bit to which follows must correspond?