Ahmad ibn Ibrahim al-Ghazi
Yeshaq (died 1578) was the Bahr Negus, or ruler of the realm of Medri Bahri in what is now present-day Eritrea during the mid to late 16th century. His support of the Emperor of Ethiopia during the invasion of Imam Ahmad ibn Ibrahim al-Ghazi (also known as Ahmed Gragn), when so many of the local aristocrats had switched their support, helped to preserve the country from extinction.