The three kingdoms of Egypt were actually time periods so they weren't ever unified. The first kingdom was the Old Kingdom which lasted from 2700 BC - 2200 BC. The second kingdom was the Middle Kingdom which lasted from 2100 BC - 1800 BC. The third kingdom was the New Kingdom which lasted from 1500 BC - 1000 BC.
They continued to grow with the uniting of northern and southern Egypt. The first one to unite this two was Menes the 1st king of Egypt. The unifying of Upper and Lower Egypt into a single kingdom is the event pointed to by the ancient Egyptians themselves as the beginning of their civilization.
Egypt and Kush united in to one kingdom.
About 3000 B.C.
Unified upper & lower Egypt maybe by military force and/or by peaceful means such as marriages or administrative measures
One of the Egypt's kingdoms are the middle, new and old kingdom's
The pharaoh Narmer, also known as Menes, was the first to unite Egypt into one empire. However, later rulers, such as Ahmose of Thebes, also united Egypt.
Upper and Lower Egypt.
menes
so he can have it for himself
Pharaoh
Memphis was the capital of old kingdom Egypt.
There is no kingdom of Egypt.