Dar Al-Islam created via dumb way (Shia Caliphate --> Brunei --> comeback to Arabia) a very pleasant campaign.
Some time ago, I wondered how to name the culture in this region. I'd like to show you how it turned out.
Initial Idea was to create Shia Caliphate in Borneo ruled by Fatimid dynasty and to form Empire of Brunei. I started as adventurer and go there after adopting Norse culture and creating religious head title. Then educated kids back to Bedouin culture. I played rather without min-maxing just for fun. It was rather tall at the begining. Blending Bedouins and Dayaks was not the brightest idea in Austronesia but with time I added few traditions connected to sea.
When I was finishing unifying Indonesia, I remembered the campaign when I was returning with the Ummayads from Andalusia to Damascus. I decided that conquering Arabia from Borneo would be fun. Along the way, Genghis Khan appeared, and I had to conquer China from him (I avoid teritorial gains there previously). You know just in case he build up to much. Fortunately, it was possible to use this casus belli, which allows us to occupy all of China.After the beatings, I made an alliance with him so that he wouldn't cause any problems in the back. Finally, I created the Dar Al-Islam with the entire area of China as de jure lands. Brunei became the center of the world.
The only sad thing is the small number of provinces in Asia compared to Europe. The entire area of my religion is just over 1,000 counties. Catholics, meanwhile, have 750 provinces. I've added a religious map to illustrate the scale.