There are two individuals by the name of Diego de Haedo in the seventeenth century with whom we are concerned. They were uncle and nephew. The older man was Archbishop of Palermo and Captain-General of Sicily, which at that time was under the sway of Spain. He collected material on the city of Algiers, in North Africa, principally because he was concerned for the large number of Christians who were enslaved there, who had been captured and sold by the Barbary Pirates. (The Jews were similarly concerned for the welfare of their fellow-religionists in slavery, and to this day the Congregation of Spanish and Portuguese Jews in London elects an official called Parnas dos Cautivos "Overseer of the Captives", who was charged with raising funds for their redemption. Of course, he no longer has any real function, but their sense of history prompts them not to abolish this obsolete office.)
The younger Diego de Haedo served his uncle for a time as his assistant, and later returned to Spain to take up a position as abbot of a monastery. In 1632 he published in Spain a book entitled Topographía e Historia General de Argel [Algiers] which he respectfully dedicated to his uncle. It includes a set of dialogues in classical vein discussing the various relevant problems. This book was reprinted 1927-29 by the Bibliophile Society of Madrid in a limited edition. A copy of the reprint resides in the library of the University of Wisconsin-Milwaukee, and several other American and European libraries.