The spread began in the 7th to 9th century, originally brought to North Africa under the Umayyad Dynasty. Trade networks were extensive, spanning through north and west Africa which created a medium in which islam peacefully spread through the merchant class.
Answer:
subtropical high pressure
Explanation:
Many desert areas are caused by subtropical high pressures. Such areas are consistently warm, dry and also sunny. And are the Arabian desert in the middle east and in Africa, the Sahara desert. It is also called the horse latitude and have it's latitudes between 30 and 35 degree in the north and south. Rainfall is supposed and winds is variable with calm winds sometimes.