It's a britsh series beacause in 1966, the New Zeland driver Bruce Mclaren founded the McLaren Motor racing F1 Team and the base of the team is Woking in England.
In 1967 Bruce McLaren decided to use a British Racing Motor on the McLaren F1 cars.
After a race won by a mclaren car, the anthem british is intoned during a podium ceremony.
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