These two videos ambushed me this morning.
On the face of it neither of them grabbed my attention, but I wasn't feeling my best (late night last night) so it was convenient to indulge YouTube with some leisurely viewing, apropos of nothing in particular.
Serendipity - the art of encountering fortuitous happenings!
These are long videos, and in a (rather extended) weak moment I watched them both to the end. They are not related except in as much as they deal with a broad sweep of history, but the presentation and subject matter is complementary.
The first is an interview of talking heads, and is probably the easier to follow, whilst the second is in lecture format (albeit quite informal) but it does have an annoying habit of showing the lecturer rather than the slides he is talking about.
And ignore the intro, it's nothing to do...