As the graves at Igbo-Ukwu show, archaeology will always have an advantage over the texts collected by Levtzion and Hopkins in their Corpus, since it will continue to provide fresh evidence for our approach to African history. For that approach, on the other hand, the texts in question provide a contemporary written record vastly superior to the meagre account of sub-Saharan Africa in Antiquity, in their reference to persons, places and events below the horizon of the Classical world. Geographically, however, their own approach to the subject remains within the confines of the Classical picture of the world. Coming after the works of al-Ya'qubi and al-Mas'udi at the end of the ninth and the beginning of the tenth century, and before those of the Andalusian al-Bakri in the eleventh and the Moroccan al-Idrisi in the twelfth, The Picture of the World by the traveller Ibn Hawqal in the second half of the tenth century illustrates the expansion of the Islamic world over the three or four hundred years of Lombard's Golden Age, but also the limits of its vision. Reliant upon reports that may or may not have been first-hand or contemporary, original or repeated from the works of their predecessors, the writers in question proceed methodically, either by route from place to place, or in the manner of Strabo and Pliny from region to region, from west to east along the bands of climate into which Ptolemy had divided the world.