Joshua not only fulfils the vocation of Moses; in his own person and his mission, he also completes the story of Joseph.
Joseph went down from the land of Canaan into Egypt as young man, hated by his brothers because he dreamed that he would rule over them. By the end of Genesis, Joseph is vindicated against his brothers who hated him, having become their saviour—and the saviour of the world.
In the story of Joshua, the exaltation of Joseph goes even further. It is one of Joseph’s sons—Joshua, of the tribe of Ephraim—who leads the sons of Jacob in their conquest of the promised land. We might even see Joshua as the quasi-king of Israel at this time. (This is suggested by the fact that, in Judges, the death of Joshua creates the conditions for the tribes to be divided and at war with each other. These national crises will not be resolved again until there is a king in Israel.)
This exaltation of Joshua also seems to be part of the pre-eminence of the second-born Ephraim over the firstborn Manasseh, according to Jacob’s blessing of Joseph’s sons:
He, too, shall become a people, and he, too, shall be great. But his younger brother shall be greater than he, and his seed shall be a fullness of nations. (Gen. 48:19, Robert Alter, The Hebrew Bible)
At the end of the book, we are told that Joshua died at one hundred and ten years old. Almost immediately after this, we are also told that the bones of Joseph, which had been brought with the Israelites from Egypt, were buried in Shechem. We might recall that Joseph also died at the age of one hundred and ten years old. This is a hint to us that we should associate Joseph and Joshua with each other; specifically, we should see that Joseph's faith was at last rewarded by the work of Joshua.
In Joshua, the son whom was feared by his father to be devoured and rent in pieces was returned home, safe and sound. What’s more, the son who was at first rejected by his brothers was later highly exalted, and his brothers came to bow before him.