Sumer was a very old kingdom that existed many, many years ago. It was located in the area we now know as Iraq, where the Tigris and Euphrates rivers flow.
People who lived in Sumer were among the first to develop writing, about 5,000 years ago. They wrote using tiny shapes called cuneiform, which were pressed into soft clay tablets.
The people who lived in Sumer built big, tall buildings called ziggurats which were like big mountains. These were used for religious ceremonies and were thought to be a pathway between the heaven and earth.
They also developed many different jobs, like farmers, craftsmen, and traders. They traded goods with other places and people. They used boats to travel on the rivers and canals they built.
Sumer was ruled by the kings, who were helped by priests and advisors. They had armies to protect themselves from invaders.
The Sumerian civilization eventually declined and disappeared for a few different reasons, including droughts and invasions. But they left behind many contributions to the world, including the invention of the wheel and plow, and the first written laws.