The first ever Varsity sporting event between Oxford and Cambridge was a two-day cricket match held on 4th June 1827 at Lords, which was then followed up two years later by the first Boat Race between the rival universities at Henly-on-Thames.
For the second Boat Race the venue was moved to London in 1836 where it was rowed over a much longer distance, from Westminster Bridge upstream to Putney Bridge. It is this event that is associated with the origin of “The Blue”
Just before the race, one of the Cambridge oarsmen decided to tie a light blue ribbon to the bows of their boat, perhaps because it was Eton's “colour” or perhaps because it was simply the only bit of ribbon he had to hand!
Soon after Oxford took on the dark blue of Christ Church College as their “colour” and began sporting white jerseys with dark blue stripes.
These colours have remained over the years and now sportsmen ( and women even!? ) who have represented Oxford in a Varsity match against Cambridge in a Full Blue sport are entitled to wear the prestigious dark blue blazer.