The Story
Cleopatra, Queen of the Nile
was the last descendant of the ancient Egyptian pharaohs.
She died in 30BC after deliberately allowing an asp (Egyptian cobra) to bite her.
Facts
It is extremely unlikely that she would have committed suicide in that manner. Asp bites aren't always fatal, and even when they are it is a slow and painful death.
Cleopatra wasn't even remotely related to the ancient Egyptian pharaohs, or any other Egyptians for that matter. (Her era was actually closer to our modern era than it was to that of the builders of the Great Pyramid.) In contemporary art, Cleopatra is depicted as having pale skin, a long straight nose, and other European features.
Modern Egyptians are mostly Arabic, but the ancient Egyptians were much darker skinned, with some African features.
Cleopatra was really Greek, not Egyptian or African. Her family tree is known for many generations, and all her ancestors were Greek. (Interestingly, where most people have 64 great-great-great-great-grandparents, Cleopatra had only two. She also married both of her brothers.)
Cleopatra was part of the Ptolemaic dynasty, a Greek family that ruled Egypt after Alexander the Great conquered Egypt in 332BC. Both the Ptolemies and Alexander came from the Macedonian region of Greece. The Ptolemies spoke Greek only, refusing to demean themselves to speak an African language. Cleopatra was the first to actually learn Egyptian.
Why
Linking Cleopatra with the Pyramids, Sphinx, and our traditional views of ancient Egypt simply makes a much better story and film than her being part of a European family that ruled over a conquered African nation.