Here is the one. Are these **** are all between us?
In our childhood religious teachings we were told that Prophet(PBUH) told not to kill children, women, old people etc.. In war only armed enemies are killed.
And after winning a war, innocent people there were never forced to accept Islam. In fact they accepted Islam themself. When they saw that enemy (muslim warriors) have not even touched them, and instead just ruling with care. They became Muslims.
This is what i know about spread of Islam.