<P> In Egyptian history, the Upper and Lower Egypt period (also known as The Two Lands, a name for Ancient Egypt during this time) was the final stage of its prehistory and directly preceded the nation's unification . The concept itself appears in titles of Egyptian Kings and Queens and appears in scenes in temple, tombs and the pyramids. Which it also refers to an innate sense of duality in the Ancient Egyptian culture . </P> <P> The Egyptian expression sema - tawy is usually translated as "The Uniter of the Two Lands" and was depicted as a human trachea entwined with the papyrus and lily plant . The trachea stood for unification, while the papyrus and lily plant represent Lower and Upper Egypt . </P> <P> Standard titles of a King of Egypt was King of Upper and Lower Egypt (written as nsw-bi.tj) and Lord of the Two Lands (written as nb - t3wy). Similarly a Queen might use titles such as Lady of The Two Lands (nbt - t3wy), Mistress of the Entire Two Lands (hnwt - t3wy - tm), and Mistress of the Two Lands (hnwt - t3wy). </P> <P> Ancient Egypt was divided into two regions, namely Upper Egypt and Lower Egypt . To the north was Lower Egypt, where the Nile stretched out with its several branches to form the Nile Delta . To the south was Upper Egypt, stretching to Syene . The terminology "Upper" and "Lower" derives from the flow of the Nile from the highlands of East Africa northwards to the Mediterranean Sea . </P>

Who united upper and lower egypt in 3100 b.c