Why are UK often divided in England, Scotland, Wales etc. in team sports but not in individual types of sports?

by kharto

In football, rugby etc. England and Wales compete as own teams but in like swimming these compete under Great Britain. Why aren't it any Scottish flagged sprinters?

joedafone

As a follow-up, I recall a lot of controversy here in the UK before the 2012 games about the possibility of creating a "Team GB" instead of the separate countries competing. Have there ever been other attempts to unite them, and what prevented those attempts from succeeding?

pbhj

As a side question: when did each individual part of the UK first field a "national" team (in any sport), preferably against another sovereign state outwith the British Isles.