Being able to see without the issue of knocking over your oil lamp in the middle of the night. Allowing people to work longer with better lighting.
Laws, they are balanced with laws.
They contributed to World War 1 through the assassination of Archduke Franz Ferdinand. The Black Hand was part of a Pan-Slavist movement in which they wanted to unite territories of South Slave that had been annexed by Austria-Hungry. Hopefully this helps.
Significant conversions also occurred beyond the extents of the empire such as that of the Turkic tribes in Central Asia and peoples living in regions south of the Sahara in Africathrough contact with Muslim traders active in the area and Sufi orders.
