עַל־כֵּ֞ן לֹֽא־הָיָ֧ה לְלֵוִ֛י חֵ֥לֶק וְנַחֲלָ֖ה עִם־אֶחָ֑יו יְהוָה֙ ה֣וּא נַחֲלָת֔וֹ כַּאֲשֶׁ֥ר דִּבֶּ֛ר יְהוָ֥ה אֱלֹהֶ֖יךָ לֽוֹ׃
Wherefore Levi hath no portion nor inheritance with his brethren; the LORD is his inheritance, according as the LORD thy God spoke unto him.—
Shenei Luchot HaBerit
When taking into consideration Ephrayim and Menashe the sons of Joseph, there are actually fourteen tribes. The land of Israel was divided up amongst only twelve tribes, however. When you deduct from the fourteen tribes the tribe of Levi, which did not qualify for the land distribution, and Joseph himself, who substituted for his father spiritually, you are left with twelve tribes. The land was divided between Reuben, Shimon, Yehudah, Issachar, Zevulun, Dan, Naftali, Gad, Asher, Benjamin, Ephrayim and Menashe.