duran is the greatest LW in history. he then moved up and beat the second greatest welterweight in history. everything after that is just gravy.
The second greatest welterweight in history is Henry Armstrong. With 20 successful defenses of the title. with wins over Ross,Arizmendi,Zivic,Jenkins,Garcia,Zurita,Rodak,Montanez etc. and in many cases he was outweighed by as much as ten pounds in some of his defenses. Leonard has some great wins at 147 but his resume isnt as deep as Hank is at the weight.