There is some interesting historical information and a second video at the bottom that are worth checking out.
This one was launched from Sweden, not the UK, and the Wikipedia article linked above suggests it has been launched from sites around the world.
Launches had been carried out from sites in Europe, Australia, and South America, with use far beyond the UK by NASA, the European Space Research Organisation (ESRO), and German and Swedish space organizations
Question: Did the Skylark ever launch from the UK? If so, roughly what fraction of the launches?
below: Image from here.