It was a common saying at Damascus that under Walíd people talked of fine buildings, under Sulaymán of cookery and the fair sex, while in the reign of ‘Umar b. ‘Abd al-‘Azíz the Koran and religion formed favourite topics of conversation.[376] Of Walíd's passion for architecture we have a splendid monument in the Great Mosque of Damascus (originally the Cathedral of St. John), which is the principal sight of the city to this day. He spoke Arabic very incorrectly, and though his father rebuked him, observing that "in order to rule the Arabs one must be proficient in their language," he could never learn to express himself with propriety.[377] The unbroken peace which now prevailed within the Empire enabled Walíd to resume the work of conquest. In the East his armies invaded Transoxania, captured Bokhárá and Samarcand, and pushed forward to the Chinese frontier. Another force crossed the Indus and penetrated as far as Múltán, a renowned centre of pilgrimage in the Southern Punjaub, which fell into the hands of the Moslems after a prolonged siege. But the most brilliant advance, and the richest in its results, was that in the extreme West, which decided the fate of Spain. Although the Moslems had obtained a footing in Northern Africa some thirty years before this time, their position was always precarious, until in 709 Músá b. Nuṣayr completely subjugated the Berbers, and extended not only the dominion but also the faith of Islam to the Atlantic Ocean. Two years later his freedman Ṭáriq crossed the straits and took possession of the commanding height, called by the ancients Calpe, but henceforth known as Jabal Ṭáriq (Gibraltar). Roderic, the last of the West Gothic dynasty, gathered an army in defence of his kingdom, but there were traitors in the camp, and, though he himself fought valiantly, their defection turned the fortunes of the day. The king fled, and it was never ascertained what became of him. Ṭáriq, meeting with feeble resistance, marched rapidly on Toledo, while Músá, whose jealousy was excited by the triumphal progress of his lieutenant, now joined in the campaign, and, storming city after city, reached the Pyrenees. The conquest of Spain, which is told by Moslem historians with many romantic circumstances, marks the nearest approach that the Arabs ever made to World-Empire. Their advance on French soil was finally hurled back by Charles the Hammer's great victory at Tours (732 A.D.). [Sidenote: ‘Umar b. ‘Abd al-‘Azíz (717-720 A.D.).]