The World at War must rank as one of the best television documentaries ever produced. Thames Television devoted three years (1971-74) to making the series, which is perhaps the most expensive documentary of all time—the entire series cost £900,000 (equivalent to roughly $16,000,000 in 2019 US dollars).
https://www.amazon.com/World-at-War-Laurence-Olivier/dp/B0002F6AH0

