The flag of Morocco (Berber: Acenyal n Umerruk, Arabic: علم المغرب‎) is made of a red field with a black-bordered green pentagram. Red has considerable historic significance in Morocco, proclaiming the descent of the royal Alaouite family from the Prophet Muhammad via Fatima, the wife of Ali, the fourth Muslim Caliph. Red is also the color that was used by the Sherifs of Mecca and the Imams of Yemen. From the 17th century on, when Morocco was ruled by the Alaouite Dynasty, the flags of the country were plain red. In 1915, during the reign of Mulay Yusuf, the green interlaced pentangle was added to the national flag. While Morocco was under French and Spanish control, the red flag with the seal in the center remained in use, but only inland. Its use at sea was prohibited. When independence was restored in 1956, it once again became the national flag. The red background on the Moroccan flag represents hardiness, bravery, strength and valour, while the green, five-pointed star represents the Solomon’s seal.