Regardless of any assertion of virtuous intent; at its core, the motivation for the building of empires, by and large, is the accumulation of wealth for the minority at the expense of the majority. There are of course other, just as avaricious, incentives for empire but they all align with its primary purpose. However, regardless of its grandeur or period of reign, following its downfall (and eventually all fall) it is judged not by its initial motivations, or by the destruction it causes whilst coming into being, and certainly not by the wealth and accomplishments it accumulates during its reign; in the end, it is judged by the legacies it leaves.
Throughout history man has built empires, one hundred and eighty seven, recorded, nation-based empires alone. The first on record, the Akkadian Empire, began in 2334 BC, and the last, the Portuguese Empire, officially ended in 1999. The empire with the shortest reign, less than two years, was the first Mexican Empire (1821 – 1823), and the longest reigning empire, the Mayan Empire (2,000BC – 1540 AD) was a staggering 3,540 years in duration.