Leah bore Reuben, Simeon, Levi, Judah, Issachar and Zebulun.
Bilhah bore Dan and Naphtali.
Zilpah bore Gad and Asher.
Rachel bore Joseph and Benjamin.
Additionally, Joseph had two sons, Manasseh and Ephraim, who's descendants are treated as their own tribes.
Now do the math
Leah bore 6 sons. Bilah bore 2 sons. Zilpah bore 2 sons. Rachel bore 2 sons. Joseph (son of Rachel) bore two sons, and he himself doesn't count. 6+2+2+2-2-1=13, not 12. Yet, even throughout the bible, Israel is often said to be the made up of 12 tribes.
Even more contradictions come from different texts in the bible from different periods.
At Deuteronomy 33, leaders of all the tribes of Israel are said to be present at a gathering to receive their tribe's blessing. The odd thing is that the tribe of Simeon isn't listed. Were they snubbed? Unlikely. Such a snubbing would be listed with reasons for condemnation. In fact, even more strange, Joseph is listed right along with his two sons as though a separate tribe from them.
There's also missing reference to a tribe in 1 Kings 11 in the prophecy regarding the brake up of the nation of Israel.
Song of Deborah
However, the biggest glaring contradiction comes from the Song of Deborah in Judges 5. "This may be the oldest textual fragment preserved in the Bible, dating to about the twelfth or eleventh century B.C....," says Gary Greenberg in his book 101 Myths of the Bible (of which most, but not all, of this blog entry is derived). The Song of Deborah records Deborah's efforts to rally the tribes of Israel against the Canaanites. It lists the tribes that heeded the call and the tribes that didn't. The names of the Israelite tribes listed in the Song of Deborah are substantially different from the traditional 12 (or 13) tribes of Israel. Gilead, Machir, Meroz are included, but Simeon, Levi, Judah, Manasseh, and Gad are not mentioned. Take a quick glance above to see who are the mothers of these missing tribes. That is an interesting nuance.
Mr. Greenberg states,"Because this is one of the oldest textual passages in the Bible, the inclusion and omission of names provides solid clues about the emergence of Israel and any connections to the sons of Jacob." Additionally, "The absence of these five tribes from Deborah's list strongly suggests that they had not yet come into existence as political entities until later and that their namesakes had no earlier existence as sons of Jacob."
Excuses, excuses
Growing up in a Christian Fundamentalist home, one thing always excused away was the inconsistencies in the number and names of the tribes of Israel. Is it 12 or 13? I count 13, but we always would say it's 12. Then, when it came time to read the Song of Deborah, the contradiction of names and number was waved off with something like "the extra tribes mentioned were actually other peoples in the area that decided to help Israel." Of course, there's no support for that statement anywhere in the bible. It was pulled out of the air by someone hundreds of years ago and has been passed along as a quick way to prevent people from questioning the contradiction; which could lead to questioning the idea of taking the Bible literally. (Oh, the horror of it all!) Also, the ridiculous excuse doesn't explain why so many of the traditional Israelite tribes are missing from the list.
Traditions
The stories surrounding each of the tribes of Israel were written long after the events listed. These stories were written as metaphors for each tribe's place in Israel. As tribes disappeared, their stories where lost, or changed to suit the newer tribes. Each tribe needed its own story in order to have a place in the Israelite nation. This political story telling was a tradition that has its origins in Egypt. The Israelite priests and leadership carried on the traditional after they were expelled from Egypt as a way to legitimately establish new political/religious structures in the new land. It is likely many of these first priests and leaders had similar positions in Egypt before their expulsion. In fact, the name of Moses himself is a clue as to the real origin of many of the stories in the Bible. More on that some other time. Hint: Hyksos.