Amenemhet I was the founder of Egypt's 12th Dynasty. In Hieroglyphic, his Throne name is sHtp-ib-Ra.w (He who pacifies the heart of Ra) and his Horus name is sHtp-ib-tA.wy (He who pacifies the heart of the two lands). He reigned in the years 1976-1947 BC, or 1938/9-1909 BC, or something else entirely depending on who you ask. Egyptian dating is an art more than a science.
Amenemhet is suspected to have been the vizier under the previous pharaoh, Mentuhotep IV, the last ruler of the 11th Dynasty. Nobody knows whether there was a violent transition between dynasties (ie, Amenemhet lived out the American dream and killed his boss), or whether they were good friends and Amenemhet took over after Mentuhotep died.
However he came to the throne, Amenemhet had a tricky situation on his hands. He needed to convince people that he was The Real Deal. There was a lot of propaganda literature at the time, like The Prophecy of Neferti, The Teaching of Amenemhet, and The Story of Sinuhe. The Prophecy is set in the time of the Old Kingdom pharaoh Snofru, who asks his advisers to tell him a story. They bring him Neferti, who prophesies a time of chaos and lawlessness, the First Intermediate Period, and foretells the coming of Ameny, a king who will set the land right again. Blind Freddy could see the transparent propaganda for the reign of Amenemhet.
As if there weren't enough confusion about Amenemhet, nobody knows how he died. Most people think that Amenemhet was assassinated, because the Teaching describes an attempt on Amenemhet's life. But others say that the attempt was unsuccessful and that Amenemhet lived on for another 20 years. In view of the fact that the Teaching specifies that Amenemhet was attacked before he made his son Sesostris I his successor, and that by the end of his life he and Sesostris had a strong association, it seems likely that the attempt on Amenemhet's life was unsuccessful.