Vansleb was to make his way to Egypt, and thence to Abyssinia, with no more apparent object than the ordinary curiosity of a traveller desirous of studying the language and the natural history of the country. In case he found influential men favorably disposed, he was to advise them confidentially that a German prince named Ernest, who held the Abyssinians in high esteem, as well for their warlike qualities as for their attachment to the ancient faith of their fathers, had given him letters for them in their own language, and that he was willing to make the necessary advances in money to bring to Europe a certain number of well-disposed young Abyssinians desirous of instructing themselves as to the condition of the Christian reformed churches, and thus bring about, between the two peoples and confessions, a sincere and lasting friendship.
In every respect the proposition suited Vansleb. The arrangement was soon completed, and he was invested with all the necessary powers of an ambassador, but in a disguised and indirect form, with special instructions not to exhibit his credentials until fully satisfied that his advances would be met.
The result of this remarkable embassy is soon told. Ludolf himself relates that he does not know whether to attribute the failure of a plan conceived with all possible prudence to the parsimony of the duke or to the imprudence of Vansleb. That Ludolf, who, after this period, never hesitated to paint Vansleb in the blackest colors, should make it a matter of doubt, is quite enough to justify the latter.
And now let us accompany Vansleb on his route to Ethiopia. He reached Cairo in January, 1664, and spent a year in visiting Egypt, and in studying and copying Abyssinian books. The Coptic Patriarch of Alexandria, Matthew de Mir, whose jurisdiction extended over the churches of Ethiopia, dissuaded Vansleb from attempting to penetrate that country, and he addressed Duke Ernest a letter in Arabic, giving the reasons for his advice, which letter is still preserved in the ducal library of Saxe-Gotha.
And now the grand project of Ernest was visited—humanly speaking—with poetic justice. The Coptic patriarch, who was pleased with Vansleb, obtained from him an exposition of the history of the reformation and of Lutheran doctrine, and Vansleb, instructed in return, could, as he listened to the patriarch, compare the German novelties with the antique symbol of the oriental communions. The result was inevitable, and he began to see a light that illuminated his mind and made evident his errors. He soon afterward embarked for Italy, fully resolved to seek admission to the Catholic Church.
Landing at Leghorn, he went to Florence, where he spent some time, and was protected by the prince, who was afterward Cosmo (de' Medici) III. Here, also, he made the acquaintance of the British ambassador, Finch, whom he subsequently met at Smyrna. Going to Rome, he there abjured Protestantism, was received into the church, and entered the Dominican convent of the Minerva. This order, specially devoted to teaching and preaching, was best suited to his tastes and habits.
And here, for a period of four years, Vansleb disappears from the world and from history. He passed them in solitude, exclusively occupied with study and religious exercises.
Meantime, imagine, if you can, the storm that broke at Erfurth. Duke Ernest was bitterly disappointed, as was natural; but it would be difficult to describe the fury of Ludolf. It burst forth never to be extinguished but with his death. Vansleb, so warmly recommended by Ludolf to the duke, suddenly became a monster not only of ingratitude, but of every other possible vice. There were no limits to the abuse nor to the accusations of the angry professor.
All this did not then trouble Vansleb, but he was made to feel their effects long afterward.