A common criticism of Caesar is that he "overran his supply lines". Is this criticism accurate? If so, how serious of an error was this? Did it ever lead to serious defeats?

I am curious about this. I don't recall Caesar out running his supplies with only a couple of possible exceptions.

There was an incident in Spain, I believe, where water was an issue and he used that as a motivating factor for his men. Basically telling them if they were thirsty they could have all the water they wanted, it was right there on the far side of the enemies camp.

During the battle of Phasalus was the truly notable exception that I can think of. In that one I am not so sure I would call it a matter of out running his supplies as it was there were simply none available. He was on foreign soil surrounded by a formidable army of Romans and Pompey's allies. In this instance Caesar did put himself in a virtually untenable position. His only supplies, really, would have to come by sea, unreliable at best. While Pompey had the entire countryside at his disposal. Both Caesar and Pompey knew that it was only a matter of time before Caesar ran out of food and so Pompey waited.

Fortunately for Caesar, the senators and men around Pompey wanted him to push the fight, which was exactly the wrong thing to do. But he eventually gave in and had his men line up for battle. This was really Caesars only chance. He had his men line up, but before they did, he had them tear down their fortifications. This would be all or nothing.

Caesar was brilliant. He managed to beat Pompey's horse by essentially laying a trap for them. They charged his smaller Calvary which fell back, only to reveal a unit of infantry armed with spears and missiles. Horses have an aversion to running into a line of spears and so they turned and ran. They were chased by Caesars horse and the infantry, which quickly found themselves on Pompey's flank. They turned and at the point the battle was pretty much settled. Caesar had done another brilliant thing to help this along. He had sent criers out to the battlefield telling Pompey's army that if any chose not to fight all they need do was drop their weapons and they would not be killed. He kept his word and on seeing their armies outflanked, many did just that. Pompey himself fled the scene under disguise.

That's the major time that sticks out in my head. Hopefully someone else can fill us in on this. I would be truly interested in seeing the answer.

Thanks for the question.