Campaigns for a return-to-nature, for health & fitness and for social nudity or naturism arose in Northern Europe in the later part of the 19thC and were gradually adopted by other European countries after the First World War.
The Hyde Park Lido built in 1930 was a concrete expression of the outcome of the movements. It gave people somewhere to sunbathe legally, as it was illegal to strip to sunbathe unless on specially designated beaches.
In North London, from 1921, people gathered at the Welsh Harp to bathe and expose their bodies to the sun.
Members of the Sun-Ray Club and the New Life Society sunbathed on the grassy banks of the Harp in various states of semi-nudity, in the belief they were protected by notices chalked on surrounding trees stating, ‘Sun-bathing Ground. Please keep away.’
Indignation simmered among the locals – for years – a toxic combination of inquisitive incomprehension, sexual repression, cheap titillation and frustration boiled over during one hot weekend in June 1930.
Scandalised (and perhaps uncomfortably seduced) by the exposed bodies of sun-bathers in a field near Sandy Cut, Cool Oak Lane, Kingsbury and outraged by the fact that nude women bathers were seen to be in the company of semi-naked men, caused a crowd of some 200 voyeurs (or local protestors) to become agitated.
Taunting turned to jeers and insults, and insults gave way to blows and threats to throw bathers into the water. Though there were no reports of serious injury, the club members, called sexual maniacs in contemporary reports, found it necessary to seek police protection.Captain H.H. Vincent, secretary of the movement, stated that the crowd appeared to take objection to one of the women, who wore nothing above the waist.
We put up notices warning people that sun bathing is taking place but they will come and stare at us, and some of them even take photographs. Dress or undress is optional with us. The objectors are ignorant people, with whom it is useless to argue.
As a result of the riots the golden era of nudity and bathing at Welsh Harp ended and the sunbathers banded together and formed a club in the altogether more bohemian environs of St Albans.