Earth's Galactic History
Throughout its history, Earth has been the stage of many acts in the play of Humanoid galactic history. Many extraterrestrial civilizations have walked the face of the Earth, both humanoid and non-humanoid races, and they have done so, long before man even existed. Together with mankind, they have written the history of this Planet.
Therefore, it is important to realize that you cannot really understand the history of mankind, nor the history of Earth, until you are aware of the part that was played by these extraterrestrial civilizations. This means, e.g., that you cannot understand the history of mankind if you do not know that Homo Sapiens was not entirely the product of a natural evolution but was in fact the result of a cross breed of genes of Terran primates, and humanoid aliens. (Not that Darwin was wrong, or that there is no such thing as evolution. But Homo Sapiens appeared too soon, too suddenly with too many distinguishing features to be the result of a natural evolution. Did you ever wonder why scientists do not succeed in finding the least trace of "the missing link" between Homo Sapiens and its predecessors? Now, you know why).
To fully understand the play and the players, it is therefore also important to realize that Earth's Galactic History is merely one part, one stage, in the bigger play of Humanoid galactic history.
In the pages on humanoid galactic history, you will find that the cradle of humanoid civilizations stood in the constellation of Lyra. From there, several humanoid species spread throughout our galaxy. Long before homo sapiens existed, Earth was thus visited by humanoid races from Lyra, Vega, Sirius, Orion and the Pleiades, and all of them established colonies on this planet. At first, only small groups of aliens settled down on Earth. Later on, however, members of the ‘Sirian Group' (i.e. a group of extraterrestrials from Sirius, Orion and the Pleiades) came in far larger numbers.
At a given moment in time, members of this Sirian Group started needing ‘workers' to assist them in colonizing the planet. Through genetic manipulation they created mankind, by blending their own DNA with the DNA of earth primates and the predecessors of man (Neanderthal).
From that moment on, Earth becomes the scene of constant disputes between, mainly, two groups of alien civilizations. On the one hand, there are the Sirians, joined by some Vegans, some (renegade) Pleiadians and some Orion civilizations, and on the other hand there are the Pleiadians and the Lyrans, also joined by some Orion civilizations. The fights nearly always were over mankind, and on several occasions, they interfered in our history. The stories of these interventions can be found in all ancient mythologies, which speak of how the 'Gods' keep on meddling in human affairs and keep on having fights among each other over these interventions... Quite often these mythological stories mention snake people, which usually is a reference to the Sirians, whereas bird, eagle or cat people usually refer to the Lyrans and Pleiadians. (Sometimes, however, the 'snake people' are a reference to a third group of aliens, the Draconian group, or 'Reptilians.' Even though there are indications that these aliens, too, have been around on this planet for tens of thousands of years, they have only recently started playing an active part in its history, again!).
It is generally believed that the aliens intervened two times in the evolution of our species. A first time would have happened, probably approximately 400,000 years ago. Some researchers believe this led to the creation of Neanderthal. A second intervention would have happened approximately 200,000 years ago, leading to the creation of Homo Sapiens. This second time, more alien DNA was used, yet at the same time, our DNA strands were reduced from twelve to two. This was done to prevent us from overtaking our alien creators on the evolutionary scale, as evolution seems to happen faster on earth. It seems, however, that they underestimated DNA's inherent desire and power for evolution, as our awareness has dramatically increased, and we seem to be catching up with them, anyway.
Apart from all the groups mentioned above, there are higher-dimensional and more advanced civilisations that keep an eye on everything that is going on here, too. Every once in a while, they, too, have made their presence known.