Military expansion. The Rashidun Caliphate expanded gradually; within the span of 24 years of conquest, a vast territory was conquered comprising Mesopotamia, the Levant, parts of Anatolia, and most of the Sasanian Empire. Unlike the Sasanian Persians, the Byzantines, after losing Syria, retreated back to Anatolia.
1 And the nature of this reality again can neither be consistently represented as a fixed and hard substance nor as an unalterable something, but only as a fixed order of recurrence of continually changing events or impressions.
Learner's definition of CONTINUUM. [count] formal. : a range or series of things that are slightly different from each other and that exist between two different possibilities. His motives for volunteering lie somewhere on the continuum between charitable and self-serving. a continuum of temperatures ranging from very cold to very hot.