After unifying Macedonia and conquering Greece, Alexander the great led a legendary campaign eastwards, conquering some of the world's most formidable armies in the process. Why would he go through all the trouble of fighting the Persians when going northwards through the Balkans or westward through Italy must have seemed so much easier pickings? Was this just him being a glory hound? Did he see Persia as a greater prize because that empire already had the foundations of a strong bureaucracy? Was he trying to preempt a historic foe he feared might attack if he didn't get them first? Do we have any insight into his mindset?