What pharaoh is responsible for uniting upper Egypt and lower Egypt?

The pharaoh responsible for uniting Upper and Lower Egypt is Narmer, also known as Menes. He is credited with the unification around 3100 BCE, marking the beginning of the Early Dynastic Period. Narmer's achievements are commemorated in the Narmer Palette, which depicts his victory and symbolizes the merging of the two regions. This unification laid the foundation for the development of ancient Egyptian civilization.