The 11th century was to prove far less stable than the 'golden age' of Umayyad al-Andalus in the 10th century. As powerbase-fortress, Marvão is likely to have played a role in civil wars among internal factions in the Badajoz taifa during the 1020-1040s. Notably, the short-lived Taifa of Lisbon (1022-1045) was to challenge Aftasid dominance in Badajoz along the traditional land trade routes linking the Tagus through the São Mamede sierra (Santarem-Caceres).