Which group of people had the earliest written language and what was it called?

It was developed by the Sumerians, an ancient civilization that lived in Mesopotamia (modern-day Iraq) around 3500-2300 BCE.

The Sumerians were the first to develop a system of writing using wedge-shaped marks pressed into clay tablets. This writing system was called cuneiform, which means "wedge-shaped" in Latin.

While some argue for the possibility of other early written languages, Sumerian cuneiform is widely accepted as the oldest one with a continuous documented history.