The history of Machu Picchu can be traced back to the ancient Inca Empire, which came into existence around 1200 ad. Furthermore, Machu Pichhu, along with the city of Cuzco, was built under the Rule of Pachacuti, and Topa Inca, as they extended their diplomatic rule over the central and southern highlands of Peru. It is believed that after its construction, Machu Picchu was used as a royal estate for emperors and nobles. There is also the belief that Machu Picchu was used as a religious site, due to its geographical location that features many aspects the Inca saw as sacred. The site was later abandoned, around 100 years after its construction, due most likely to the Spanish invasion of the 1530’s. Not much was know about the site after this until 1911, when the archeologist, Hiram Bingham, claimed to have discovered the site. In July of 1911, Bingham climbed to the top of the two mountains where Machu Pichhu lies, where he was met by a young man who led him to the stone terraces of the site. While Bingham is the most well known for the discovery, it is believed that many other missionaries and explorers had reached the site, but had not been as vocal about their findings.
Here is a short video that extends upon the history of Machu Pichhu:
https://www.youtube.com/watch?v=BeyZxu3mW-Y#t=23