These were built in the late 16th century, mostly by Sultan Ahmad al-Mansur.[4][3] Two other bastions, Borj Twil and Borj Sidi Bou Nafa', were also built along Fes el-Jdid's walls south of Borj Sheikh Ahmed.[3] The Borj Nord, Borj Sud, and these bastions (sometimes referred to as the bastioun in Arabic) of Fes el-Jdid are the only fortifications in Fes to demonstrate clear European (most likely Portuguese) influence in their design, updated to serve as defenses in the age of gunpowder. Some of them may have been built with the help of Christian European prisoners of war from the Saadians' victory over Portuguese at the Battle of the Three Kings in 1578.[4][25]