History begins with the invention of writing. People sometimes talk about the "history of the universe" or the "history of coral reef formation", but those things aren't really history. They're just a bunch of shit that happened.
History began with the invention of writing. Before that, there was no actual history, just a bunch of poorly dressed frat boys hitting each with rocks. Also dinosaurs. To be clear, we mean that dinosaurs are from before history officially began, not that cavemen hunted them or domesticated them or something. That would be stupid.
Writing was invented independently at several different points, and spread by diffusion from there. The invention of writing systems was pivotal, as it enabled us to make accurate records that could be referred to later. It was a vast improvement over the previous system, which depended on old people remembering things.
Although we don't have records for this period, we have managed to piece together a few things. For example, we have reason to believe that the first human ancestor to use tools and fire was Homo Erectus, winner of the award for species whose name is most likely to cause immature giggling.
Homo Sapiens (like modern humans, but not as fat) first evolved sometime between 400 and 25 thousand years ago. Lots of things then proceeded to happen, but none of them count as history, for the aforementioned reasons. Instead, we've got a bunch of myths and legends that changed so much in the telling that we don't really know what they're about anymore. For example, many cultures have legends about some hero who stole fire from the gods and spends eternity getting punished for it. This was probably originally a story about some poor fucker getting hit by lightning, thereby neatly combining the theft and punishment in one stroke.
After discovering hunting, gathering, fire and rocks, the human race hit a slump and wandered around for tens of thousands of years, just leading a nomadic existence. By 12,000 years ago, we had managed to colonize just about every part of the planet that wasn't actually covered in ice or under the ocean. Then we got bored and invented agriculture.
The invention of agriculture allowed more and more humans to gather together in one place for long periods of time and trade diseases. But it wasn't just primitive undertakers who benefited. A relatively stable supply of food soon allowed for more people to engage in specialized professions, such as soldiers to fend off the attacks of all the nomads who rejected the invention of agriculture in favor of the older invention of stealing.
Cities were typically founded on the banks of rivers, because they handily combine the functions of toilet, garbage dump, corpse removal system and clean water reservoir. Also some people like to swim.
By 3,000 BCE, civilizations had developed in Mesopotamia, Egypt, India and China. Although primitive and constructed mostly out of mud, these early cities provided many of the same benefits we take for granted today, such as not being eaten by lions as often and being enslaved.
Complex religion is also thought to have developed during this time. Many ancient people worshipped the Sun and Moon, and believed fervently in ghosts and magic. Luckily, we live in the future, and nobody takes that stuff seriously anymore (see 5 Ridiculous Ancient Beliefs That Thrive on the Internet).
The combination of civilization and the Agricultural Revolution lead to something that had literally never occurred before: people felt safe. For the first time, the average person had a reasonable expectation of getting food every day, and there was very little chance of being eaten by lions while going about their day-to-day business. Naturally, this lead to a outpouring of goodwill and fellowship that invited all people to come together in peach and brotherhood.
Just kidding. They attacked the shit out of every other city in sight, sometimes razing the city to the ground, taking the children into slavery, raping all the women, and cutting the men's penises "like a cucumber." Seriously, ancient people were dicks (see The 5 Most Terrifying Civilizations in the History of the World).
Many empires rose and fell over the centuries, many of them leaving significant and lasting contributions to our current civilization. So it's kind of unfair that we're going to focus entirely on Rome. We're even skipping Ancient Greece.