Adam Clarke on Exodus 1:8

There arose up a new king - Who this was it is difficult to say. It was probably Ramesses Miamun, or his son Amenophis, who succeeded him in the government of Egypt about A. M. 2400, before Christ 1604.

Which knew not Joseph - The verb ידע yada, which we translate to know, often signifies to acknowledge or approve. See Jdg 2:10; Psa 1:6; Psa 31:7; Hos 2:8; Amo 3:2. The Greek verbs ειδω and γινωσκω are used precisely in the same sense in the New Testament. See Mat 25:12, and 1Jn 3:1. We may therefore understand by the new king's not knowing Joseph, his disapproving of that system of government which Joseph had established, as well as his haughtily refusing to acknowledge the obligations under which the whole land of Egypt was laid to this eminent prime minister of one of his predecessors.