The decipherment of Babylonian ultimately led to the decipherment of Akkadian, which was a close predecessor of Babylonian. The actual techniques used to decipher the Akkadian language have never been fully published; Hincks described how he sought the proper names already legible in the deciphered Persian while Rawlinson never said anything at all, leading some to speculate that he was secretly copying Hincks. They were greatly helped by the excavations of the French naturalist Paul Émile Botta and English traveler and diplomat Austen Henry Layard of the city of Nineveh from 1842. Among the treasures uncovered by Layard and his successor Hormuzd Rassam were, in 1849 and 1851, the remains of two libraries, now mixed up, usually called the Library of Ashurbanipal, a royal archive containing tens of thousands of baked clay tablets covered with cuneiform inscriptions.