Conquest is hardly a new theme in human affairs. One of the most dramatic events of prehistory was the vast expansion of the Indo-Europeans, whoever they may have been. Their linguistic and cultural conquest seems to have extended to nearly all of Europe and vast chunks of Asia. In most cases that conquest does not seem to have annihilated the conquered peoples, so some sort of colonization must have occurred, with the conquerers dominating culture and language but being gradually absorbed into the local gene pool.
Similar events seem to have occurred with subsequent historical empires like those of Alexander, Rome, and Mohammed. Such episodes of conquest seem more likely to originate on the fringes of the highest civilizations rather than the center: from Macedonia and Rome, not Greece and from Arabia and Mongolia rather than from Constantinople or China.
The overseas European empires that arose in the 15th century are not too alien to the pattern. The dominant seapower at the dawn of the 15th century was China, and her ships were much larger and probably more seaworthy than the Spanish and Portugese ships that reached the Americas and Asia at the end of that same century. It is one of the great ironies of history that China, at the apex of its seagoing power, voluntarily abandoned the oceans. One can hardly doubt that the history of the world would have been quite different if a fleet of Chinese ships like those of Zhang He in 1408 had shown up in the Canary islands in 1450 or so.
In any case, that Chinese decision to abandon the sea condemned it and Asia to half a millenium of subservience to the Western powers.