Moawia, the first Khalif of the Omaiyides, endeavoured to purchase this sacred mantle from Ka'b for ten thousand pieces of silver, but the offer was refused. Later on it was, however, bought from Ka'b's heirs for twenty thousand pieces of silver, and it passed into the hands of the Khalifs, and was preserved by them as one of the regalia of the empire until Baghdad was sacked by the Mughals. The mantle, or what is supposed to be the self-same mantle, is now in the treasury[2] of the Sultan Khalif of the Ottomans at Constantinople, in an apartment named 'The Room of the Sacred Mantle,' in which this robe is religiously preserved, together with a few other relics of the great prophet. [Footnote 2: _Apropos_ of this treasury, it is much to be regretted that a complete catalogue of its contents has never been prepared along with a brief historical account of them. It is difficult to obtain the order, which comes direct from the Sultan, to visit the collection; and even then visitors are hurried through at such a pace that it is impossible to examine with minuteness the many curiosities collected there.] Ka'b has thus come to be considered as one of the friendly poets, and the names of two others are also mentioned, viz., Abd-Allah bin Rewaha and Hassan bin Thabit. On the other hand, the most celebrated antagonists who attacked Muhammad, not only with their verses, but also with their swords, were Abu Sofyan, Amr bin Al-'A'asi, and Abd-Allah bin Zobeir. These three became great political characters, but later on made profession of Islam, and were the staunchest supporters of it, rendering the greatest services to the Prophet during his life, and to the cause after his death. But Muhammad's greatest triumph over the poets was the conversion of Labid, who, after the perusal of the commencement of the second Surah of the Koran, tore down his own poem, which was hung up in the Kaabah, and ran to the Prophet to announce his conversion, and to make his profession of Islam. Even Ali, the cousin, son-in-law, and first convert of Muhammad, was a poet, but it is uncertain which of the Diwans attributed to him are genuine, and how many of his maxims of wisdom, over a hundred in number, are his own. During the period under review the number of Arabic authors was legion. Some idea of the number of writers, and of the subjects on which they wrote, can be gathered from the Fihrist of An-Nadim, from Ibn Khallikan's Biographical Dictionary, and from Haji Khalfa's Encyclopaedia. With such a mass of information as is contained in the above-mentioned works, it is difficult to deal in a small work. To put them together in an intelligible form, the idea of classing the authors, according to the subjects on which they principally wrote, naturally presented itself. This plan, therefore, has been followed, and a few details of the most celebrated writers will be given, classified under the following heads: