The period before written records were invented around 5,000 years ago is known as prehistory. Most of what we know about this time comes from remains left behind, such as tools, bones, and ruined buildings. Until recently, it was difficult to tell how old these objects were, but scientific advances have allowed us to put together a much clearer picture of not only human history, but also the origin of life on Earth, and even of the Universe itself.
13 billion years ago
The Universe comes into existence with the Big Bang. Over billions of years, stars, galaxies, and eventually our own solar system were formed.
5 billion years ago
The Sun, planets, and other objects that make up our solar system are formed.
4 billion years ago
Life begins on Earth. The first forms of life on Earth were simple organisms, but they evolved over time into the many varieties of plants and animals known today.
250 million years ago
Dinosaurs become the dominant life form on Earth. Millions of years ago, dinosaurs walked, swam, or flew on Earth. Until they became extinct, they were the dominant animals on the planet.
65 million years ago
The dinosaurs die out in a mass extinction event.
7-6 million years ago
Apes in Africa evolve the ability to walk upright.
1 million years ago
The ancestors of humans begin to use fire. The ancestors of humans, known as hominins, evolved from tree-dwelling apes. Over time, they began to use tools and make fire.
200,000 years ago
Modern humans first appear in Africa.
The development of farming allows people to produce their own food.
Early farmers establish the first villages. Communities begin to construct walls around their settlements. Early humans moved from place to place in search of food. With the development of farming, people built villages and worked the land.
Metal-working begins in Mesopotamia in West Asia. As humans discovered the technology of creating items from copper, bronze, and iron, they crafted stronger tools and weapons.
The first great cities arise in Mesopotamia. Some villages continued to grow, becoming towns and eventually cities. These population hubs were bustling centers of trade.
The first wheels used for transportation appear in Mesopotamia. The wheel was one of the most important technological developments of the prehistoric era. Invented
independently by different cultures around the world, the wheel revolutionized transportation. It was also crucial to later advancements in farming, construction, industry, and engineering.
The Egyptians develop hieroglyphs, the first system of writing. With the invention of writing, people could leave records to be read by later generations. The period known as prehistory came to an end.