Commander Shepard ;)

Genghis Khan he was a ruler as well as a great commander. If he was immortal he would of probably rule the world.

For the modern era, the best general is undoubtedly Gustavus Adolphus Magnus of Sweden - the father of modern warfare. He developed combined arms which was used throughout the rest of the modern era, through to the end of World War I. He devised methods of warfare which allowed his tiny Swedish army to defeat many German states, Poland, the Empire of the Danes, and the Russian Empire. He established the Swedish Empire and made it, in a very short period and with a very small army, the dominant force in Northern and Eastern Europe, and probably the smallest military force to ever achieve such grand power.

Napoleon was heavily influenced by him, as were all the great generals of that era, but Napoleon's greatness came as the result of brute force, he had the largest military force the western world had ever seen, only the likes of Constantine and maybe Diocletian's combined Tetrarchy compared.

Caesar I think was greatest of all time, because he too had a relatively small military force, but was incredibly versatile in his tactics, and smashed every army sent against him. He was unpredictable, he conquered Rome with only ONE legion, he was the father of the Roman Empire, and expanded her territories more greatly than anyone else had. Marc Antony was also great, before he went mad with power in Egypt, described himself as a living God and attempted to conquer all of Asia! After tens of thousands of his soldiers died in the deserts - it left an opening for Octavius to sail south and defeat him.

Bismark, used the divide and conquer technique (Caesar used this a lot to defeat his enemies) in that he established alliances between nations, and then declared war on individual nations including Austria, Denamrk, and France, defeating each of them with ease - and eventually bringing most of the German states under his control in what became the nation of Germany.

Friedrich II was the most successful suicidal military leader in history (although I think many felt that about Caesar and Constantine as well, and both of them were more successful, so maybe most successful suicidal military leader in modern history), a small army of something like 55,000, and he had essentially declared war against earth - the French Empire, the Swedes, Austria, Spain, Russia, Denmark, German states, the Danes - and managed claim a draw against the coalition forces. Although he didn't really gain much, he created a legend of Prussian superiority, which would help lead the Prussians (and by extension the Germans) to become the most powerful nation in the world a hundred years later.

Also, thumbs up to the guy who mentioned Subotai of the Mongols. Certainly one of the very greatest.

What about Khalid ibn al-Walid or the Sword of God.

He was a General who sided with the Prophet Mohammed when Islam was created. He helped secure Islam in Arabia then conquered Iraq, captured Syria and Damascus, Jerusalem and most of the Holy land.

I am not Muslim, however he was never defeated and was able to defeat the Byzantine and Persian Empires in conflicts.

He was actually so talented he even defeated the Prophet Mohammed in a battle.

en.wikipedia.org/wiki/Khalid_ibn_al-Walid

People wonder how Islam spread so fast and he was a big reason.

http://en.wikipedia.org/wiki/Khalid_ibn_al-Walid

Very good pick =)

Although I wouldn't actually call the Empire that he invaded the Byzantine Empire - rather I would take it further and say that he was the one who smashed the spine of the Eastern Roman Empire, and that the Byzantine Empire emerged afterwards as a successor state. The Western Empire was said to have fallen earlier, but in actuality, it was still Roman (it still had a senate and was culturally identical) - just run by certain Germanic Kings who were running the west in the name of the Eastern Roman Emperor. It was only after the Islamic armies defeated the Southern part of the Roman Empire and the Visigothic Kingdom that the culture and state of the Roman Empire was truly defeated.

Yeah the most interesting thing he defeated the Prophet in a battle.

Well actually, Mohammed knew he would try to outflank by taking the cavalry around the hill so he put archers to guard the rear. When the Islamic forces were winning the archers joined the battle and left the rear exposed and Khalid ibn al-Walid charged from the rear and defeated the Prophet Mohammed in a battle.

Genghis Khan or Alexander the Great, but I'm not an expert on the subject.

Edit: Apparently, Tsubodai was Genghis Khan's general, so him instead of Khan.

Hannibal, not only for feats on the battlefield but also boldness and innovation and problem solving skills logistically.

Alexander would be my first choice. At 29 he had conquered the biggest empire, destroying big powers (most notably persians). He died so young from sickness.

Napoleon was good too, eventough he lost at the end, he was owing the whole Europe during 10 years against multiples countries.

Gengis Kahn was a great military strategist as well, but he did not fight the best european armies.

It's all in context really, I suppose. For example, Alexander the great was a fantastic conqueror, but he was king of a nation. Would he have been able to start from grass roots like Cromwell?