Scholars have debated whether homosexuality or merely a love of books prevented a ruler from this city from producing an heir until he bestowed a male name and clothes upon his wife Subh. In this city, the enslaved mathematician Lubna is said to have overseen a massive library. A ruler of this city constructed a fortified palace on its outskirts called the “Radiant City.” To align with existing Roman streets, (-5[1])this city’s (*) “Great Mosque” was oriented towards the south. This city’s political demise resulted in the establishment of the taifa kingdoms. After winning the Battle of Musarah, Abd al-Rahman I established a namesake independent emirate ruled from this city. For 10 points, name this foremost city of Umayyad al-Andalus, where a namesake caliphate was later established in 929. ■END■ (10[1])