No god but God by Reza Aslan is a good text that discusses the history and development of Islam, starting with a political and economic examination of pre-Islamic Arabia. It is an extremely good and extremely easy read.

It’s how I know that there were religious pilgrimages. There were idols all over… for a while, anyway. Funny story, one clan straight up stole everyone’s religious idols and brought them to the Kaaba and charged everybody admission to get in and pray.