Further, summer raiding campaigns from both Christian and Moorish forces effectively meant that the regions between the Douro river and Tagus were under continual threat - the lands south of the Douro and to the north of the Tagus became a depopulated 'buffer zone' between Christian and Moor. In 1063, a major razzia by Ferdinand sacked towns across the Seville and Badajoz taifas, and the São Mamede mountains lay en route. To make matters worse, the taifa of Badajoz was also fighting a war on its southern front: the taifa of Seville, under the poet-emirs Al-Mutamid and Al-Mutatid - was eating into territories in the Algarve .