Back issues of the Christian History magazine available to read or download as pdfs
5 Minutes In Church History - a series of short podcasts by Dr Stephen Nichols.
The History section of Christianity Today - some full articles are available. Others require a subscription. A lot of the unavailable material is available on the Christian History Institute website.
This website was created by AI given a small handful of prompts. It shows a church history timeline. Clicking on an event shows a little more information.