[Vicomte13]

Seems to me that to decide who were "The Greatest", you have to establish some criteria.

There were many, many decisive battles fought over the course of history and many great commanders, so if we're really going to pick the GREATEST, we've got to settle on what constitutes that.

The results that flowed from a given engagement are a criteria for the MOST IMPORTANT commanders in history, but that does not necessarily mean the best commanders in a military sense.
One of the most important battles in all of history was fought on the Plains of Abraham beside Quebec City in 1759. The armies were tiny. It was a battle of liliputians for the prize of a continent. Few battles have had as many dramatic long-term results. What was written sometime in the 1800s by a great historian is true: With the fall of Quebec begins the history of the United States, and few things in history have had such dramatic results as the establishment of the American Republic.
However, I don't think that we would want to call either Montcalm or Wolfe the greatest military commanders in history. They were both competent military men, but both also made some ghastly mistakes.

I would propose that the criteria for military greatness need to be focused on military capacity itself, in a professional sense. And I think that we must limit ourselves to higher command. There have been some absolutely brilliant soldiers and sailors, whose single-handed actions changed the course of battles. But that is not command.

So, I would propose the following criteria for establishing who were truly the greatest military commanders of all time.
(1) They had to be in high command, either on the land or on the sea (or in the air). Unit command can establish a great tactician, but the greatest military commanders OF ALL TIME must be master tacticians AND master strategists.
This eliminates the Stuarts and Forrests (and Custers?) from the list.
(2) They had to win every battle they ever commanded.
This seems like a shocking requirement, but it is an important one. We are sifting through history here to try and determine those men actually in high command, whose tactical and strategic brilliance is unmatched in history.
There are generals and admirals in their age who changed the face of the world who won every battle they ever fought, demonstrating that NOBODY in their epoch had mastered the military art of their age greater than they.

One single defeat does not mean that a commander was not great, but it's just like football scores. At the end of the season, the team with an unbeaten record is BETTER than the team with one loss and one tie (assuming they're playing in the same league).

So, when we sift through history to find UNBEATEN high commanders, the list dramatically shortens.

Gengis Khan drops off of it. He sent a fleet unprepared into a hurricane and lost the Japanese campaign. The GREATEST commanders mastered both the land and supply by sea.

Every American general or admiral drops off of it (Eisenhower lost Market-Garden). They were all defeated at one point except for him. Patton was defeated at the first Kasserine Pass.

Hannibal and Napoleon lost in the end. They went far, but in the end they were bested, which means they were not the greatest: there were men in their times who were as good or better, obviously: they got beaten, after all.

Alexander the Great was never defeated. He is one of the greatest.
It is debatable whether or not Julius Caesar was defeated by the Celts in Britain. I personally believe that he made peace with Casselvelanus because he was unable to defeat him.
Charlemagne was repulsed in Spain. He falls off the list.
Attila the Hun was beaten at Chalons-sur-Marne. He falls off the list.

Marlborough held high command and beat large professional armies, and was never defeated. He is on the list.

Lord Admiral Nelson was the greatest naval commander in history. Like Jellicoe, he defeated a mortal threat. Unlike Jellicoe, he did so DECISIVELY. Merely winning is not the mark of a great commander. Winning every battle, and winning an overall decisive victory in the great battles: that is the mark of military genius.

Clive of India is an interesting candidate, although the forces under his command, and those of his enemies, were not so redoubtable as to be able to compare him with men commanding great armies and navies in the face of other world-class armies and navies. Beating up on ill-organized native levies is victory, but it is not the same thing as defeating the French Army under Napoleon.
This, incidentally, is why there is nothing in the medieval period that stands out among the greatest. The armies were very small, and the results were very inconclusive in almost every case, Tours being perhaps the one exception. I do not know enough about the rest of Charles Martel's MILITARY career to be able to say much. Nobody who won one battle or one short campaign is among "the greatest military commanders of all time". A professional life of military victory is required.

Wellington is an interesting case. I don't know if he suffered any reverses or fought battles in Spain to a draw.
Marlborough and Nelson and Alexander did not fight to draws. And that is an important distinction between them.

So, Wellington's a maybe, depending on details of the Spanish campaign that I don't know.

Was Zhukov ever defeated? I don't think he was. He would qualify.

I don't believe that Guderian or Von Manstein were ever defeated either. The Russian winter slowed them, but they were not defeated. Hitler fired them and didn't bring either of them back, if I recall. Up until that point, I believe they had an unbroken series of the most amazing victories in history.

So, using those criteria, here is the very short list of the truly greatest military commanders of all time: professional full-time military men, who possessed high command, who showed both tactical and strategic brilliance of such a surpassing quality that they were never once defeated by any of their peers over long careers:

CERTAINLY:
Alexander
Marlborough
Nelson

MAYBE:
Caesar
Wellington
Zhukov
Guderian
Von Manstein

There have been many greats, but they all fall short of perfection in high command. To be the greatest, you have to be perfect.

[indcons]

"Gengis Khan drops off of it. He sent a fleet unprepared into a hurricane and lost the Japanese campaign. The GREATEST commanders mastered both the land and supply by sea."

That was Kublai Khan and not Genghiz Khan. Genghiz never lost a war in his glorious military career that spanned over 50 years.

[investigateworld]

I'd prolly cut Patton some slack as to North Africa. FDR was under a lot of pressure from the "Second Front Now" crowd, still a major component of the Democrat party.

[luvbach1]

With the length of this thread, easy to see we have mucho retired military, and military buffs, at the keyboard.

[porkchops 4 mahound]

I agree that "greatest" is too wide of a window, if you are a person accustomed to measurable variables.

The entire premise of the question is likely flawed, in that the demands of time and place change what is "great".

I don't think winning every time is tied to "greatness", maybe because of my Celt blood?

Leonidas, King of the Spartans, and his 300 Spartans, and 1100 Thespians, against hundreds of thousands of Persians, at Thermopaleae, in 480 BC?

Vercingetorix, who at Alesia (52 BC), did everything wrong, while Caesar did everything right.

Boadicea (Boudicca) queen of the Iceni against the Romans (60-61 BC)

Or the last queen of Carthage, whose name is unknown to me, who threw her children back into her burning city, and then jumped into the same fire after them, rather than joint her husband in disgrace and dishonor, who had just surrendered Carthage to the Romans who were putting the entire city to the sword except him and his family?

I know we are talking military commanders but, you just cannot ignore the traditions of self aware sacrifice, examples of leaders, if not truly Commanders.

It seems to me, that batting a thousand, is not a reasonable requirement for greatest military commander. In fact, it is how great commanders deal with defeat, that shows the depth of their greatness.

Jes my .02

[Tallguy]

Patton was defeated at the first Kasserine Pass.

IIRC, Patton was not in command at Kasserine. The command structure prior to Pattons arrival AFTER Kasserine was part of the problem. Eisenhower was aloof & passive at the time. II Corps was commanded by Lloyd Freydendahl at Kassarine and I think he was operating under the direction of a British General (Anderson?).

Anyway, I think Patton had his faults, but Kasserine was not his failure as he was still back at Casablanca playing host to FDR & Churchill.

[Tallguy]

I don't believe that Guderian or Von Manstein were ever defeated either.

Von Manstein failed to get into Kursk. He got beat.

I think that the 'undefeated criteria' is a little unfair. Sometimes a general is just handed a losing hand and the best he can do is mitigate a defeat (MacArthur in the Philippines; Lee in the Wilderness, etc.) I don't think Phil Sheridan was ever defeated. He was a good general at the tactical & strategic levels, but one one of the greats, IMHO.

[x]

That's a good analysis, but I'm not so sure that it comes down to being undefeated. Some commanders have a bad hand to begin with and have to make the best of it. Others, fighting for extremely powerful nation can win wars easily without being exceptionally gifted.

And there have been generals like Washington, who were frequently defeated but still achieved their goals. They weren't the greatest of generals, but do they count as "winners" or "losers"?

Also, a general or army that was top flight in its prime might decay over time to the point where a lesser commander can beat them. I'm not convinced that if we examine their whole careers, that Wellington would come off a better general than Napoleon.

Even if Wellington does come out better for his victory, it doesn't mean that Napoleon -- whatever his faults -- wasn't one of history's greatest commanders.