So how did he do this?

He mastered the art of warfare. Soon after he took the throne he quelled a brutal uprising, and took over neighboring lands with determination and strength. More importantly, though, is that he treated conquered lands fairly. He didn't take a huge taxes from the lands he took over and leave them to govern themselves; the lands were integrated into his empire through a central government. He also rewarded bravery and talent of any individual, regardless of his background. What began as a military show of strength turned into a program of assimilating all those in his path, in every aspect of life. This resulted in loyalty from his subjects.

Akbar was a brilliant and cunning military leader

Under him, the Mughal empire changed from an unstable fiefdom to the vast kingdom seen at the right.