With the help of the Ethiopian defector Harb Jaush, who also served as a commander under his brother Sabr ad-Din II, Jamal ad-Din was able to defeat the armies of the Ethiopian Emperor in three important battles in Bale, at Yedaya, and at Jazja, although he was eventually defeated. Jamal ad-Din sent an envoy to arrange peace at the beginning of his reign, but the effort failed and Harb Jaush engaged and was able to overcome the Emperor's troops, reportedly including 7,000 archers and swordsmen. Yeshaq responded by gathering a larger army and occupying Yedaya before being repulsed by Jamal ad-Din's forces. His army then took Jazja, although here, too, Jamal ad-Din was able to successfully counter-attack and force the imperial army to withdraw, allowing the forces of the Adalite Sultan to pillage the region over the next three months. Following this success, he organized another successful attack against the Emperor's forces and inflicted heavy casualties in what was reportedly the largest Adalite army ever fielded. As a result, Yeshaq was forced to withdraw toward the Blue Nile over the next five months, while Jamal ad-Din's forces pursued them, while looting much gold on the way, although no engagement ensued. After returning home, the Sultan sent his brother Ahmad with Harb Jaush to successfully attack the Ethiopian province of Dawaro. Despite his losses, the Emperor Yeshaq was able to continue to field armies against the Walashmas. After another campaign by Jamal ad-Din against the Ethiopian frontier, Yeshaq sent his forces to attack three different areas of Adal, threatening the capital and seat of the ruling Walashma family. Jamal ad-Din was forced to return to Adal where he fought Yeshaq's forces at Harjai, where his soldiers were defeated. According to al-Maqrizi, Yeshaq was said to have died during this battle, although it is not mentioned in the Ethiopian Royal Chronicles of Yeshaq.
Death
Within a few years, however, Jamal was assassinated by either his friends or cousins around 1432 or 1433. He was succeeded by his brother Badlay ibn Sa'ad ad-Din.
