Maḍmūn ben Japheth מַצְמוֹן בֶּן יֶפֶת

Maḍmūn ben Japheth ben Bundār (d. 1151) was the son of Japheth ben Bundār, "chief of the congregations" and representative of the merchants at Aden in the late eleventh century, and the pivotal figure in Aden's history. He was at once nagid of Yemen and wakīl al-tujjār, "representative of the merchants"—that is, he ran the port's customs house.

What that meant in practice is visible in the Genizah letters. His house served as post office and warehouse for the whole Egypt–India route: goods were left there, letters collected there, money held there. He owned ships sailing to Ceylon. He negotiated safe passage with tribal chiefs and with pirate captains—one letter calls him "the confidant of rulers, whether on the sea or in the desert." After him his son Ḥalfon ben Maḍmūn took over.

Institutionally, Aden under him was tied to Egypt: its court acknowledged the jurisdiction of the Egyptian centre, and Aden together with some twenty Indian ports and Ceylon formed a single rabbinic district. Maḍmūn sent halakhic questions with lavish gifts to the head of the Palestinian yeshiva resident in Fustat—and thereby drew the displeasure of the pro-Baghdad party. Aden's merchants sent money to Maimonides, and his son Rabbi Abraham later answered their queries.

One persistent confusion should be cleared. Ḥalfon ben Nethanel ha-Levi al-Dimyāṭī was an Egyptian India trader, the travelling companion and patron of Judah Halevi; Ḥalfon ben Maḍmūn was the Adeni nagid's son and successor. They are two different men, and even reference works conflate them.

And one more. The goods of this trade were not spices, as is usually written. In Goitein's documents the staples are pepper, brazilwood, iron and steel, textiles and bronze vessels; aromatics are a minority of the cargo's value. Yemen exported to India and imported for Egypt, and made its money on the intermediation.