A naive question perhaps, but...

Let me start out by saying, that I have just now (in my late 20s) become interested in boxing - I watched some fights as a teenager and was able to name some names, but overall I had little to no clue about the sport and it´s adherents.

Still, even back then, if someone had asked me about whom I would consider the "greatest boxer of all time", I would have possibly replied "Muhammed Ali". Why? Dunno, perhaps because he was/is so present in the media, there were/are so many films and documentaries about him, his face was unrecognizable, plus I heard (even back then) that he has a pretty respectable boxing record.

Now that I have begun to brush up my knowledge about boxing (and picked it up as a hobby), I would like to return to this issue. I watched some older fights on Youtube and I am now able to reognize respectable technique when I see it. I am still far away from claiming any expertise neither on Ali nor any other fighter, all I can say, is that Ali is a pretty good boxer, but so is/was Louis, Marciano, Tyson and Frazier. Let me stress that I have no real preference or favoritism within this issue - discussions about who is "the greatest boxer" are as old as the sport itself, and the discussions usually go nowhere - I would just like to know where - in your opinion - this enduring image of Ali as "the greatest" came from (apart from him saying so).

Whenever this issue is raised, people will usually start with "his speed, agility and reflexes", but honestly, this doesn´t really do anything for me me. I do know enough to say that it´s next to impossible to decide on the "greatest athlete" (no matter what discipline) by one, and just one category alone - one boxer may be quicker, one has the better chin, one is the better puncher, so this really is not that useful as an argument. His boxing record? Undeniably impressive, but if we take that as a standard, Marciano would take the title, as he has retired undefeated.

Don´t get me wrong (I´ve seen enough more than one debate about this issue turn ugly very quickly) - I am not aiming for a "is he overrated"/ "would he stand a chance against xx"-discussion - my simple (and naive) newbie-question is - what is it, that made Ali become such an icon? Why are there dozens of documentaries about him, and not an other boxer, why can you find his poster (the Phantom-Punch) in every other student room and why is his face on dozens of t-shirts all over the world.

I could accept that his involvement in the civil rights movement and his protest against the Vieman draft elevated him from a mere athlete to a political figure who was willing to suffer for what he believed in - but still, this would just make him a great person, and has little to do with his performance in the ring. From what I have seen I wold definitely take him as one of the greatest - but I just can´t get my head entirely around the myth that surrounds Muhammed Ali, the man and his fights.

As I said, personally, I think that it´s probably impossible as such, to nominate the one best athlete of all time - still, I would appreciate if some people could shed some lights on the issue. What is it that makes Ali the greatest? What sets him apart from other great fighters?
And of course some contributions from people who disgree are also welcome - just try to keep personal reservations out of the debate, and also don´t engage in comparisons with other boxers, as this usually does not lead anywhere.

Thanks in advance!