Albert Barnes Commentary 1 Kings 11:40

"Solomon sought therefore to kill Jeroboam; but Jeroboam arose, and fled into Egypt, unto Shishak king of Egypt, and was in Egypt until the death of Solomon." — 1 Kings 11:40 (ASV)

Compare 1 Kings 11:26. Ahijah's announcement was soon followed by Jeroboam's rebellion. As Solomon’s glory faded, his oppression became greater and more selfish, and a prospect of deliverance arose from Jeroboam's personal qualities (1 Kings 11:28). Consequently, the tribe of Ephraim to which he belonged once again aspired to its former position (see the note on Joshua 17:14).

Jeroboam, being active, energetic, and ambitious, placed himself at their head. However, the move proved premature. Solomon's power was too firmly established to be shaken, and the hopes of the Ephraimites had to be deferred until a more opportune time.

The “exact” date of Jeroboam’s flight into Egypt cannot be fixed. It was certainly not earlier than Solomon’s twenty-fourth year, since it occurred after the building of Millo (1 Kings 11:27), but it may have been several years later.

Shishak – This king is the first pharaoh mentioned in Scripture who can be definitively identified with a known Egyptian monarch. He is the Sheshonk (Sheshonk I) of the monuments and the Sesonchosis of Manetho. The Egyptian date for his accession is 980 or 983 B.C., which synchronizes, according to the standard Hebrew reckoning, with Solomon’s thirty-second or thirty-fifth year. Sheshonk I left a record of his expedition against Judah, which aligns well with what is related of Shishak in 1 Kings 14:25–26 and 2 Chronicles 12:2–4.