How old was Joseph when he became ruler of Egypt?

Thirty, in one verse

Joseph was thirty years old when he stood before Pharaoh king of Egypt. Joseph went out from the presence of Pharaoh, and went throughout all the land of Egypt.

The age arrives after the fact, like a stamp on the page. In a single scene Joseph has come up from a dungeon, shaved and changed, and walked out second only to the king: “Only in the throne I will be greater than you” (41:40).

Thirteen years at the bottom

Genesis gives no year-by-year account of the time between seventeen and thirty, only stages:

1. Slave. Bought by Potiphar, captain of Pharaoh’s guard, he rises to run the whole household (39:1–6).
2. Prisoner. Falsely accused by Potiphar’s wife, he is put in “the place where the king’s prisoners were bound” (39:20), and soon runs that too (39:22).
3. Forgotten. He reads the dreams of the cupbearer and the baker, who stay in prison “many days” (40:4). The cupbearer, restored to his post, forgets him (40:23).
4. Two more years. Pharaoh dreams “at the end of two full years” (41:1).

Joseph summed up that time himself in the names of the two sons born to him before the famine. Manasseh: “God has made me forget all my toil, and all my father’s house.” Ephraim: “God has made me fruitful in the land of my affliction” (41:51–52).

What Pharaoh gave him

• His signet ring, which sealed orders in the king’s name (41:42).
• Robes of fine linen, the dress of Egypt’s elite.
• A gold chain around his neck, the kind of collar Egyptian kings gave to favored officials.
• His second chariot, with criers in front shouting “Bow the knee!” (41:43). The Hebrew word, abrek, is obscure, possibly Egyptian.
• A new name, Zaphenath-Paneah (41:45). Nobody is sure what it means. Ancient Jewish translators read “the man to whom hidden things are revealed”; the Egyptologist Georg Steindorff proposed “the god speaks and he lives”; Jerome’s Latin Bible made it “savior of the world.”
• A wife, Asenath, daughter of Potiphera, priest of On, the city the Greeks called Heliopolis.

Why thirty?

Genesis does not explain the number, but thirty keeps turning up in the Bible as the age when public service begins. Levites entered their work at the Tent of Meeting “from thirty years old and upward” (Numbers 4:3). “David was thirty years old when he began to reign” (2 Samuel 5:4). And Luke says that Jesus, when he began to teach, “was about thirty years old” (Luke 3:23).

Joseph would be thirty-nine when his brothers finally learned who the governor was. The years from seventeen to thirty-nine, and his father’s age along the way, are in how old Joseph was when he was sold; the dream that opened the dungeon door is in Pharaoh’s dream.