“Mindful and fully aware the Bodhisatta, the Being Dedicated to Enlightenment, appeared in the Heaven of the Contented… For the whole of that life-span the Boddhisatta remained in the Heaven of the Contented… Mindful and fully aware the Bodhisatta passed away from the Heaven of the Contented and entered his mother’s womb…As soon as the Bodhisatta was born, he stood firmly with his feet on the ground; then he took seven steps to the north, and, with a white sunshade held over him, he surveyed each quarter. He uttered the words of the Leader of the Herd: ‘I am the Highest in the World, I am the Best in the World, I am the Foremost in the world; this is the last birth; now there is no more renewal of being in future lives.’” – The Buddha 
Reliable scholarly translations of the Tipitaka are freely available in English on the internet. If you read them you’ll discover that “Buddha” is not a name but a title meaning “Enlightened” or “Awakened”. The “Enlightened One” or “Awakened One” is Siddhatta Gotama, a noble warrior prince who became disenchanted with the human condition of birth, ageing, sickness and death and wished for a solution. Gotama renounced his luxurious life and embarked upon a spiritual quest at the age of 29. After six years of intense mental and physical training that almost killed him, he eventually found the Middle Way between hedonism and asceticism that enabled him to achieve Buddhahood – the condition or rank of a Buddha or Enlightened One.
These early Buddhist scriptures also reveal that Gotama lived many previous lives as a Bodhisatta, one who has vowed to become a Buddha by cultivating the “ten perfections” of generosity, morality, renunciation, insight, energy, patience, truthfulness, resolution, loving-kindness, and equanimity. Gotoma Buddha is actually the seventh Buddha in a line of Buddhas that stretches back hundreds of thousands of years and will continue far into the future. The account of Gotama’s birth is miraculous (see above quotation) and he is said to have been born with thirty two marks of a “Great Man” – bizarre physical characteristics that include, for example, webbed toes and fingers, extremely long arms, a thousand-spoke wheel sign on each foot, a well-retracted male organ, a golden-hued body, forty teeth, and a fleshy protuberance on the crown of his head. , 
On attaining enlightenment Gotama Buddha wandered around Northern India conversing with gods and humans, teaching his doctrines and performing miracles (clairvoyance, invisibility, teleportation, etc.) He gathered many followers before dying eventually at the age of 80. Inevitably there were disagreements on matters of doctrine and practice and the community of monks and nuns and lay followers began to splinter into factions. The Buddha’s teachings evolved and multiplied as they were recited and eventually written down throughout India and beyond.
According to the scriptures, when all of Gotama Buddha’s remains (bones, relics, sermons, etc.) eventually disappear from this world it will be a dark time for all. However when the time is right an eighth Buddha, Metaya, will appear to continue the teaching of the Buddhas and bring light into the world once more.
Can such ancient mythology be used to construct a reliable factually correct biography of Siddhatta Gotama – the “historical buddha”? I don’t think so. Unfortunately the scriptures are all that we have. I see no reason for believing that these ancient doctrines contain the kernel of an earlier non-religious philosophy taught by a wandering contemplative who was “just a man”. More often than not the only evidence I see being cited for such conjecture is the very same texts that are being rejected as religious corruption!
In short, the more we understand the myths and legends of the Buddha the less likely we are to view them as “popular Buddhism” – degeneration from reason (philosophy) to religion (mythology). The Buddha of the Pali Canon taught liberation not attachment. His truth isn’t a matter of historical factual correctness – it’s a matter of the presence or absence of mental suffering when we internalise the message and strive to live up to it.
 The Life Of The Buddha According To The Pali Canon (3rd Ed), translated by Bhikkhu Nanamoli. Buddhist Publication Society, 1992. (pp. 3 – 5.)
 ‘The Marks Of The Superman’ (DN 30) translated from the Pali by and
 See also, ‘Lakkhana Sutta: The Discourse on the Marks’ (DN 30), translation and commentary by Piya Tan, The Dharmafarers, 2007.