@JuanArango wrote:
We would need to find out on which streaming platform it premiered.
I found an article (https://senalnews.com/en/content/zed-will-produce-10-exclusive-films-for-curiosity) saying it was produced for Curiosity Stream, Amazon Prime UK mentions Curiosity and gives dates (https://www.amazon.co.uk/Besieged-Fortresses/dp/B08RQ7M9X5), Curiosity itself doesn't show upload dates - at least for unregistered (https://curiositystream.com/video/2500) . Dates are same as on other website - https://www.yidio.com/show/besieged-fortresses
P. S. Official website says 4 episodes, but English-language websites mention only 3