Jon (or Leutholf), a learned writer, was born at Erfurt, in Thuringia, on the 15th June 1624, and received a university education at Leyden, where he devoted his study chiefly to law and oriental languages. He held successively the position of tutor to the sons of the Swedish ambassador at Paris, and to the children of the Duke of Saxe-Gotha at the court of that prince. By the aid of a native of Abyssinia, whom he met at Rome in 1649, while on a literary commission, he mastered the Ethiopic language,—an achievement never before accomplished by any European,—and published in 1661, at London, a dictionary and grammar of that tongue, which he afterwards brought out in a more improved form at Frankfort in 1698 and 1702. His knowledge of languages was exceedingly extensive; and he spared no labour by travel, study, and converse with learned men, to make himself what he ultimately became—one of the most distinguished orientalists of his age. He died at Frankfort-on-Main, on the 8th April 1704.

In addition to those already alluded to, the most important of Ludolph's works are:—Grammatica Lingua Amharica, quae vernacula est Habessinorum; adjectum est Lexicon Amharico-Lat., 2 vols., folio, Franc. 1698; Historia Ethiopica, sive descriptio regni Habessinorum, folio, Franc. 1681; Ad suam Historiam Ethiopicam Commentaria, 1691; Relatio Nova de haberdino Habessine statu Leguminum ex India super altata, 1693; Appendice continens Dissertationem de Locustis, 1694; A New History of Ethiopia, &c. (an English edition of his Historia Ethiopica), folio, London, 1684.