Islam was spread by armies, traders, and preachers called

must repent and believe in god.

or the book

journey across time - chapter 10 "the rise of christianity"

d. dr. francis collins

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.

this is a good question! i'll do some research and come back when i have the answer!