Based on the book of kings, when David's original kingdom was split, the northern kingdom (which was eventually lost) consisted of ten tribes, while the southern kingdom had two (Judah and Benjamin). However, according to the book of Joshua there were two tribes south of Benjamin, Judah. which controlled all the territory, and Simeon, which was allocated cities within the territory of Judah. Simeon had been punished (along with Levi) for massacreing a Canaanite city (see Genesis), by not being given any land, although Levi ended up as the priestly tribe. Since Joshua preceded kings, I suspect that there were only nine tribes north of Benjamin.