to that act of aggression until 1617 when he raided several Funj provinces. This mutual raiding finally escalated in a full-fledged war in 1618 and 1619, resulting in the devastation of many of the Funj eastern provinces. A pitched battle was also fought, claimed by the Ethiopian sources to have been a victory, albeit this is posed doubtful by the fact that the Ethiopian troops retreated immediately afterwards. After the war, the two countries remained at peace for over a century. The Funj sultan who ruled during the war, Rabat I, was the first in a series of three monarchs under whom the sultanate entered a period of prosperity, expansion and increased contacts with the outside world, but was also confronted with several new problems. In the 17th century, the Shilluk and Sennar were forced into an uneasy alliance to combat the growing might of the Dinka. After the alliance had run its cause, in 1650, Sultan Badi II occupied the northern half of the Shilluk Kingdom. Under his rule the Funj defeated the Kingdom of Taqali to the west and made its ruler his vassal. Decline Sennar was at its peak at the end of the 17th century, but during the 18th century, it began to decline as the power of the monarchy was eroded. The greatest challenge to the authority of the king were the merchant funded Ulama who insisted it was rightfully their duty to mete out justice. In about 1718 the previous dynasty, the Unsab, was overthrown in a coup and replaced by Nul, who, although related to the previous Sultan, effectively founded a dynasty on his own. In 1741 and 1743 young Ethiopian emperor Iyasu II conducted first raids westwards, attempting to acquire quick military fame. In March 1744 he assembled an army of 30,000–100,000 men for a new expedition, which was initially intended as yet another raid, but soon turned into a war of conquest. On the banks of the Dinder river the two states fought a pitched battle, which went in favour of Sennar. Iyasu II, traveller James Bruce noted, plundered his way back to Ethiopia, allowing him to display his campaign as a success. Meanwhile, Badi IV's repulsion of the Ethiopian invasion made him a national hero. Hostilities between the two states continued until the end of Iyasu II's reign in 1755, tensions caused by this war were still recorded in 1773.