If you are referring to who it was that founded the Buddhist faith, the correct answer is that a man named Siddhartha Gautama was the founder of the religion. He has come to be known as "the Buddha."
Although Siddhartha Gautama is believed to be a real historical person, historians are not really clear as to when he actually lived. People used to believe that he lived from abut 560 BC, but now most scholars say he died around 400 BC.
He founded Buddhism by becoming "enlightened" and then spreading the word about how to act so as to become enlightened. This was the basis of the Buddhist faith.
Buddhism is one of the major religious and philosophical traditions in the world. It began over 2,500 years ago in northeast India, with the teachings of Buddha.
Buddha (563? to 483? B.C.) was son of king Shuddhodana of Kapilvastu. He was named Siddhartha Gautama by his father. Disenchanted by seeing the miseries of the world in form of old age, disease, and death, at the age of 29, he gave up his princely life including his wife and son in quest of peace and deliverance from miseries of life.
After wandering, learning from other great teachers of his time, practicing asceticism and seeking the the peace for 6 years, the right path or means of attaining true peace and happiness in life dawned upon him with absolute clarity while he was meditating under a tree on the outskirts of village Gaya.. This event is describes as reaching enlightenment or realization as per Hindu philosophy and tradition. He was conferred the title of Buddha, meaning the enlightened one, in recognition of this enlightenment.
Buddha spent the next 45 years travelling round northeast India preaching to people, and debating with many other religious teachers. He spread hi teaching with the help of five men who became hi close disciples.
Buddha was able o spread his teaching considerably within Northern India during his life time. His work was continued after his death by his disciples and a fairly well developed organization of monks. However the credit for spreading Buddhism beyond India goes to a great extent to King Ashoka.
King Ashoka (272?-232 B.C.) ruled the Maurya Empire in India from about 272 B.C. until his death. He waged many wars to extend his empire. However he conquest of Kalinga, in which his armies killed about 100,000 people 150,000 prisoners brought a sudden change in his life and thinking. Horrified at the Kalinga carnage he renounce warfare, adopted Buddhism, which among other principles was based on practice of non-violence. For the rest of his life played a very important role in popularising Buddhism in India and many other countries.