The YouTube channel The Exploring Series had a video about some of the lore of the Warhammer 40,000 franchise called Exploring Warhammer 40k: Introduction To The Timeline:
This video followed some of the timeline of the lore of Warhammer 40,000 (Warhammer 40K).
I knew nothing about this franchise so all of this was completely new to me other than me hearing that some of it seemed to be influenced by some of the lore of the Dune franchise, and I definitely saw some examples of what it probably borrowed from that franchise.
This video only covers some of the lore, it sounds like a large and interesting world that they built here, and I am curious to learn more.
Good job The Exploring Series.