Convert to Islam or die.
This is not, nor has it ever been a central tenet of Islam. This cannot be viewed in political or historical isolation.
"Convert to Christianity under Papal authority or die by red-hot poker" was a governing principal of church and state - at the center of Europe's most powerful empire, for nearly 200 years. It was never the message of Jesus, regardless of your belief in Christianity. But scripture and political expropriation of pseudo-theology made that it seem so.
I hope someday you have a daughter who marries a an African Muslim. You might be forced to reconsider many of the things that you "know" so assuredly.