Manahem, from a Hebrew word meaning "the consoler" or "comforter;" was a king over Israel and the son of Gadi, according to the chronology of Kautsch (Hist. of O.T. Literature, 185), from 743 B.C.; according to Schrader, from 745-736 B.C. William F. Albright has dated his reign to 745 BCE-738 BCE, while E. R. Thiele offers the dates 752 BCE-742 BCE.
He came from Tirzah to Samaria to slay Shallum by his own hand, and succeeded him as king (2 Kings 15:14). He brutally suppressed a revolt at Tiphsah (so the name in the Masoretic text; modern commentators and translators prefer the reading Tappuah, following the Lucian recension of the Septuagint), and ripped unborn children from the wombs of their mothers (15:16). During his reign Tiglath-Pileser III, king of Assyria, invaded Israel with a powerful force, but was induced to leave by a gift from Menahem of 1,000 talents of silver, raised from a levy of 50 shekels on each "person of means" (15:19-21). Tiglath-Pileser records this tribute in one of his inscriptions.
The reign of this military adventurer is important from the fact that therein the Assyrians first entered the land of Israel. "And Phul, king of the Assyrians, came into the land, and Manahem gave Phul a thousand talents of silver" (2 Kings 15:19). It is now generally admitted that Phul is Tiglath-Pileser III of the cuneiform inscriptions. Phul was probably his personal name and the one that first reached Israel. His reign (745-728 B.C.) had begun at most two years before Manahem's. The Assyrians may have been invited into Israel by the Assyrian party. Osee (A.V. Hosea) speaks of the two anti-Israelitic parties, the Egyptian and Assyrian (vii, 11). The result of the expedition of Tiglath-Pileser was an exorbitant tribute imposed upon Rezin of Damascus and Manahem of Samaria (Mi-ni-hi-im-mi Sa-mi-ri-na-ai). This tribute, 1000 talents of silver (about $1,700,000 circa 1900) was exacted by Manahem from all the mighty men of wealth. Each paid fifty shekels of silver -- about twenty-eight dollars. There were, at the time, then, some 60,000 "that were mighty and rich" in Israel. In view of this tribute, Tiglath-Pileser returned to Assyria.
Manahem seems to have died a natural death, after reigning for about ten years. He left the throne to his son Pekahiah. The author of the Book of Kings describes his rule as one of cruelty and oppression.