Joshua 16:1 – 17:18 provides details about the allotment given to the tribes of Joseph. It can be divided into two parts:
The boundary allotment for Ephraim (Joshua 16:1–10)
The boundary allotment for Manasseh (Joshua 17:1–18)
The tribe of Joseph follows Judah. According to the normal inheritance rules, Joseph would be near the end since he was the eleventh son of Jacob (Genesis 35:23–26). However, he received the rights of the firstborn son (1 Chronicles 5:1–3) thus inheriting a double portion (Deuteronomy 21:17). He was given this right on account of Reuben’s adultery with Bilhah (Genesis 35:22) and possibly also his actions in Egypt. Jacob’s specific blessing for Joseph promised fertility and prosperity for their tribe (see Genesis 49:22–26), and indeed they came to be the most influential tribe in the north.1
1 The allotment of the people of Joseph went from the Jordan by Jericho, east of the waters of Jericho, into the wilderness, going up from Jericho into the hill country to Bethel.