What were causes of the rise and decline of the Meroe Kingdom, and what was the ruler of Meroe called?

Kush was an ancient Nubian kingdom in what is now modern Sudan in Africa. The city of Meroe was located along the middle stretch of the Nile River where the Blue Nile, White Nile and River Atbara run together. At its peak, the Kush Kingdom of Meroe  stretched for over 600 miles north to south along the Nile River. The physical aspects of the geographic location of Meroe likely contributed to its rise as one of the most powerful of ancient African kingdoms. The seasonal flooding of the Nile River helped create rich iron ore deposits in the region. Gold was also plentiful and Meroitic industry began with the mining of these raw materials. The close proximity of rich timberland to Meroe supported the operation of bloomeries and possibly blast furnaces as well, to work the iron and gold into tools, weapons, and jewelry. Meroitic metalworkers were among the best in their contemporary world. Furthermore, the nearby river system provided access to the River Niger and other major trade paths to the rest of Africa, as well as India and China. Flourishing industry and trade, and the wealth that came with it, appear to have been major factors in the political stability and peaceful expansion of Meroe during its heyday.

The prominence of the artisan caste in Meroe could have been a contributing factor in the atypical degree of consent between the rulers of Meroe and the ruled, in a socioeconomic system based more on labor than land ownership or control. The Kush king was selected from among members of the royal family by the Kush nobility and was an administrator of law and custom as interpreted by the priests, rather than an autocratic lawmaker in his own right. In addition, the mother of the King played an important role in rule of Meroe, especially during a period of transition from one reign to the next. A Kush king was often succeeded by his queen (called a "kandake"), lengthening the period of consistent executive rule considerably and creating another layer of political stability.

Rome's conquest of Egypt ushered in a period of conflict between Roman Egypt and Kush that sapped Meroitic power and hindered external trade. By the 1st or 2nd century CE, the decline of Meroe was underway and demand for their traditional industries collapsed with their external trade abilities soon to follow. Sometime between the 3rd and 4th centuries CE, the royal power emanating from Meroe was no longer relevant and the Meroitic state disintegrated.