This sort of informal dancing has probably been going on ever since musicians started having sessions in pubs but it's perhaps best to date it from The Oxford Folk Weekend in April 2018 when the upstairs room in the St Aldates Tavern was given over to the musicians for a session. Late in the evening, after the "official" festival dances were over, some of the dancers went to the pub and started dancing...
It was rather fun and some of us thought it ought to happen more often.
We already knew of dancing at the Bath and Bristol French Sessions, so we knew it could work and all it needed was a little help. So we branded the idea "Bal Miniscule" and got busy:
Our first "official" event (if you can call it that) was on 26 November 2018, where there was a French music session at the The Bell Inn at Adderbury. After some discussions with the musicians via Facebook a few dancers went along and danced. Only 3 people danced but it was a start.
On 10 December 2018 we went to the French Session at the Port Mahon in Oxford and had up to 7 people dancing.