Proto-Semitic is the hypothetical proto-language of the Semitic languages. The most probable Proto-Semitic Urheimat is the Arabian peninsula. This hypothesis is based on fact that the Canaanite, Aramaic, and Arab nomadic tribes are recorded to have emerged from there. The same area of origin is likely for the Akkadians. The earliest attestations of a Semitic language are in Akkadian, dating to ca. the 23rd century BC (see Sargon of Akkad). Early inscriptions in the (pre-)Proto-Canaanite alphabet, presumably by speakers of a Semitic language, date to ca. 1800 BC. Proto-Semitic would most probably have been spoken in the 4th millennium BC, roughly contemporaneous to Proto-Indo-European. The distribution of the related Afro-Asiatic languages, and especially the Egyptian branch most closely related to Semitic, suggest an original immigration of the Proto-Semites to the Arabian peninsula from the Horn of Africa, but assumptions about such early times are necessarily speculative.