Prehistory
J.M. Roberts goes into extensive detail about what is history versus what is prehistory. Most people picture prehistory as a time when neanderthals roamed Europe, and early man fought one another for control of fire; however, prehistory is more complex than that. True Homo Sapiens Neanderthalis did exist in prehistory, but he is a relatively recent creature, dying out only about twenty thousand years ago.
Our own species, Homo Sapiens Sapien, has been around for about 150,000 years, which is quite amazing considering civilizations only started appearing about six thousand years ago. Mankind has possessed the intelligence to build modern cities, technology, and methods of science, but he didn't develop his knowledge sufficiently until very recent. Our modern world has only been in existence for two hundred years, and our current technological state has only been around for thirty or so years.
Prehistory extends further back than Homo Sapiens, back to the first hominids, the first mammals, and indeed, even back to the beginning of life itself. Prehistory can include the birth of the planets, the genesis of the solar system, or even the creation of the universe. There's no major dispute over when prehistory begins: When it ends is where complications arise.
History begins not with the ascent of modern man, but with the invention of writing. Man must keep records in order for a period to be considered history. History begins in Asia Minor, with the Sumerians, but even while man made his first explorations to Antarctica a little over one hundred years ago, the Eskimos of Alaska still were in a period of Prehistory. Prehistory ends differently for each group of people. History must be recorded in writing. Until then, it is prehistory.