it's been 20 years since i took my history of islam class but i seem to recall the caliphate concept disappeared within a century or so of muhammad's death - it's periodic re-invention since then was generally the product of zealots like those of isis-fame
that said, the history of the first caliphate i recollect was actually extremely moderate in terms of imposing its beliefs on non-arabs - "people of the book" aka christians and jews were protected, and anyone in conquered lands could practice their chosen faith, albeit being required to pay a higher tax
The Caliphate lasted until the 20th century, dude.
Anyways, hope you had a good Dead Bird Day!