The Arabian Peninsula was largely arid and volcanic, making agriculture difficult except near oases or springs. The landscape was thus dotted with towns and cities, two prominent ones being Mecca and Medina. Medina was a large flourishing agricultural settlement, while Mecca was an important financial center for many surrounding tribes. Communal life was essential for survival in the desert conditions, as people needed support against the harsh environment and lifestyle. Tribal grouping was encouraged by the need to act as a unit, this unity being based on the bond of kinship by blood. Indigenous Arabs were either nomadic or sedentary (or bedouins), the former constantly travelling from one place to another seeking water and pasture for their flocks, while the latter settled and focused on