MADMŪN BEN JAPHETH BEN BUNDĀR (d. 1151), son of the first *nagid of the Jews of South *Yemen. Madmūn continued in his father's position as the "official of the merchants" in *Aden, representing the merchants who traded with India, and in this capacity was also the leader of the Jews and the nagid of the communities of South Yemen. Dozens of letters have been preserved in the *Genizah which were written to or by him, as well as court actions connected with his name and poems in his honor. More details are known about him than about any other nagid of Yemen from the 11th to the beginning of the 14th centuries. He was in charge of the port of Aden and supervised the customs payments. He formulated the agreements about prices of merchandise and his house served as a post office for the Jewish merchants, as well as a warehouse for merchandise. He owned ships which sailed from Aden to Ceylon. Among his wide-ranging activities, he jointly owned a ship with a vizier in Yemen. In a court action he is named "the confidant of rulers whether on the sea or in the desert," which means that he was held in esteem by the Muslim rulers and drew up agreements with tribal leaders and the leaders of pirates in order to assure free navigation on the sea routes between Egypt and India. In the above-mentioned court action it is stated that he was "appointed on behalf of the rashei galuyyot ["exilarchs"] and the rashei yeshivot ["academy heads"]." It is not clear whether the reference here is to the exilarch in Babylon or to a person representing the exilarch who lived in Yemen; there is an hypothesis that the reference is to the bet din in *San'a. Rashei yeshivot refers to the Palestinian academy in Egypt.
Maḍmūn maintained close contact with the gaon Maz-li'aḥ b. Solomon ha-Kohen, who was active in 1127–39 as head of the Palestinian academy which moved to Egypt as a result of the conquest of Palestine by the Crusaders. Maḍmūn sent the gaon questions on halakhah, together with expensive gifts which were also given to the scholars of his academy. He ordered that the name of the gaon be mentioned in the reshut prayer after the name of the exilarch. His attachment to the Palestinian academy aroused the opposition of the supporters of Babylonia. In documents he is called "the nagid of God's people, the minister of ministers, head of the communities." The Tunisian merchant Abraham b. Peraḥyah b. Yiju writes of him in his eulogy: "with seven names given by the exilarch," among which are mentioned, alluf, nagid, and friend of the academy. When he died, his eldest son, Halfon, who is also called nagid, continued in his father's position in economic and public life.
J. Mann, in: HUCA, 3 (1926), 301–3; E. Strauss, in: Zion, 4 (1939), 217–31; S.D. Goitein, in: Sinai, 33 (1953), 225–37; idem, in: Sefer ha-Yovel… M.M. Kaplan (1953), 45, 51–53; idem, in: Tarbiz, 31 (1962), 357–70; idem, Bo'i Teiman (1967), 15–25; idem, in: JQR, NS, 53 (1962), 97; E. Subar, ibid., 49 (1958/59), 301–9.