Albert Barnes Commentary Ezra 4:20

"There have been mighty kings also over Jerusalem, who have ruled over all [the country] beyond the River; and tribute, custom, and toll, was paid unto them." — Ezra 4:20 (ASV)

Mighty kings ... - If this reference can scarcely have been to David or Solomon (see marginal reference), of whom neither the Babylonian nor the Assyrian archives would likely have had any account - it would probably be to Menahem (2 Kings 15:16) and Josiah (2 Chronicles 34:6–7; 2 Chronicles 35:18).