ARZILLA, a very ancient maritime town of Africa, in the kingdom of Fez. Alphonso king of Portugal took it by assault, and brought away the presumptive heir of the crown. After that prince came to the throne, he besieged it, in 1508, with 100,000 men; but was obliged to abandon the undertaking. However, at length the Portuguese forsook it of their own accord. W. Long. 5. 30. N. Lat. 35. 30.