The Mamelook Sultans of Egypt seem to have taken a particular interest in this, the most Northern province of their empire, which was even then in danger of being conquered by the Turks.  In the autumn of 1477 Sultan Kait Bey made a journey of inspection, visiting Antioch and the valleys of the Tigris and Euphrates with a numerous and brilliant escort.  This tour is briefly alluded to by Moodshireddin p. 561; and by WEIL, Geschichte der Abbasiden V, p. 358.  An anonymous member of the suite wrote a diary of the expedition in Arabic, which has been published by R. V. LONZONE (’Viaggio in Palestina e Soria di Kaid Ba XVIII sultano della II dinastia mamelucca, fatto nel 1477.  Testo arabo.  Torino 1878’, without notes or commentary).  Compare the critique on this edition, by J. GILDEMEISTER in Zeitschrift des Deutschen Palaestina Vereins (Vol.  Ill p. 246—­249).  Lanzone’s edition seems to be no more than an abridged copy of the original.  I owe to Professor Sche’fer, Membre de l’Institut, the information that he is in possession of a manuscript in which the text is fuller, and more correctly given.  The Mamelook dynasty was, as is well known, of Circassian origin, and a large proportion of the Egyptian Army was recruited in Circassia even so late as in the XVth century.  That was a period of political storms in Syria and Asia Minor and it is easy to suppose that the Sultan’s minister, to whom Leonardo addresses his report as his superior, had a special interest in the welfare of those frontier provinces.  Only to mention a few historical events of Sultan Kait Bey’s reign, we find that in 1488 he assisted the Circassians to resist the encroachments of Alaeddoulet, an Asiatic prince who had allied himself with the Osmanli to threaten the province; the consequence was a war in Cilicia by sea and land, which broke out in the following year between the contending powers.  Only a few years earlier the same province had been the scene of the so-called Caramenian war in which the united Venetian, Neapolitan and Sclavonic fleets had been engaged. (See CORIALANO CIPPICO, Della guerra dei Veneziani nell’ Asia dal 1469—­1474.  Venezia 1796, p. 54) and we learn incidentally that a certain Leonardo Boldo, Governor of Scutari under Sultan Mahmoud,—­as his name would indicate, one of the numerous renegades of Italian birth—­played an important part in the negotiations for peace.

Tu mi mandasti.  The address tu to a personage so high in office is singular and suggests personal intimacy; Leonardo seems to have been a favourite with the Diodario.  Compare lines 54 and 55.

I have endeavoured to show, and I believe that I am also in a position to prove with regard to these texts, that they are draughts of letters actually written by Leonardo; at the same time I must not omit to mention that shortly after I had discovered

these texts in the Codex Atlanticus and published a paper on the subject in the Zeitschrift fur bildende Kunst (Vol.  XVI), Prof.  Govi put forward this hypothesis to account for their origin: