The tripods is a series produced by BCC in the 80s based on the trilogy by John Christopher.
There are 2 seasons produced.
All episodes are published on this channel.
Please subscribe to watch them all!
https://www.youtube.com/channel/UCDYLWEP-lPx0242n5e3saaw
I also recommend to read the 3 books (The White Mountains, The City of Gold and Lead, The Pool of Fire).
Synopsis:
The year is 2089. An alien race stalks the land in lowering machines known as the Tripods. They have taken over the earth and enslaved mankind with a mind-controlling device, ceremoniously implanted at the age of fourteen. Will Parker anxiously awaits this ritual but hears of a place where a group of people is organising a resistance movement. Together with his cousin they leave their village, hoping to join them. They have not left unnoticed however, and the giant alien machines are in pursuit.