I thought the video "History of the Internet" gave a very clear explanation on the origins of the internet. The diagrams were very helpful in understanding how the different systems worked, especially ARPANET.
I also learned a lot from the video. I didn't know that when computers were first used that most of the work was done on a separate computer, not on the mainframe computer. I found it interesting that in England NPL was designed on a commercial basis whereas in America the internet was designed for military and security reasons.