Now there arose up a new king over Egypt
Stephen calls him another king, ( Acts 7:18 ) one of another family, according to Josephus ^F7; who was not of the seed royal, as Aben Ezra; and Sir John Marsham ^F8 thinks this was Salatis, who, according to Manetho ^F9, was the first of the Hycsi or pastor kings that ruled in lower Egypt; but these kings seem to have reigned before that time, (See Gill on Genesis 46:34) and Bishop Usher ^F11 takes this king to be one of the ancient royal family, whose name was Ramesses Miamun; and gives us a succession of the Egyptian kings from the time of Joseph's going into Egypt to this king: the name of that Pharaoh that reigned when Joseph was had into Egypt, and whose dreams he interpreted, was Mephramuthosis; after him reigned Thmosis, Amenophis, and Orus; and in the reign of the last of these Joseph died, and after Orus reigned Acenehres a daughter of his, then Rathotis a brother of Acenchres, after him Acencheres a son of Rathotis, then another Acencheres, after him Armais, then Ramesses, who was succeeded by Ramesses Miamun, here called the new king, because, as the Jews ^F12 say, new decrees were made in his time; and this Pharaoh, under whom Moses was born, they call Talma ^F13, and with Artapanus ^F14 his name is Palmanothes:

which knew not Joseph;
which is not to be understood of ignorance of his person, whom he could not know; nor of the history of him, and of the benefits done by him to the Egyptian nation, though, no doubt, this was among their records, and which, one would think, he could not but know; or rather, he had no regard to the memory of Joseph; and so to his family and kindred, the whole people of Israel: he acknowledged not the favours of Joseph to his nation, ungratefully neglected them, and showed no respect to his posterity, and those in connection with him, on his account; though, if a stranger, it is not to be wondered at.

FOOTNOTES:

F7 Antiqu. l. 2. c. 9. sect. 1.
F8 Canon. Chron. Sec. 8. p. 107.
F9 Apud Joseph. Contr. Apion. l. 1. sect. 14.
F11 Annal. Vet. Test. p. 17. 18.
F12 T. Bab. Erubin. fol. 53. 1.
F13 Juchasin, fol. 135. 2.
F14 Apud Euseb. Praepar. Evangel. l. 9. c. 27. p. 431.

Taken from John Gill's Exposition of the Bible

Exodus 1:8 In-Context

6 Now Joseph and all his brothers and all that generation died,

7 but the Israelites were exceedingly fruitful; they multiplied greatly, increased in numbers and became so numerous that the land was filled with them.

8 Then a new king, to whom Joseph meant nothing, came to power in Egypt.

9 “Look,” he said to his people, “the Israelites have become far too numerous for us.

10 Come, we must deal shrewdly with them or they will become even more numerous and, if war breaks out, will join our enemies, fight against us and leave the country.”