It was 26 episodes each about 45 minutes long. It took me a few weeks to watch them all. It was made in the early 60’s and is probably the definitive documentary series on WWI.
I can’t recommend it enough. There was so much film footage and pictures that I’d never seen before. It is all black and white as you’d expect since it was made in the 60’s and is WWI footage. Quite a few good interviews with Vets as well most of who were probably in their 60’s when it was made.