Alnwick Market Place hosted bull baiting from at least the 18th century, but almost certainly much earlier.

Bull baiting involved a bull tied to the ring. Spectators would bet on one of a number of dogs who would hold onto the bull's nose for the longest. It was a brutal sport and was outlawed in 1835, but Alnwick and Morpeth were among the last of those to still host it in the region. Shoemakers were the known breeders of the dogs who would be especially bred to tug the nose of the bull. It did still likely cease by 1835 due to its bad and inhumane reputation.

"A large circular stone with a hole on the centre sunk level with surface (probable date 1765) there a large iron ring inserted in the centre of the stone to which the bulls were secured when the vulgar sport of bull bailing was practiced here. This amusement discontinued about the beginning of the present century at which time the iron ring was removed but the stone still remains. The mile distances on all the roads leading from Alnwick ae measured from this object". - from the Northumberland Name Books https://namebooks.org.uk/browse/main/?OSref=335&Page=33.0

A piece from the Northern Weekly Gazette on 06/08/1898 does state the iron bullring could still be seen in the pavement, however this could be a reproduction given the notes for the first Ordnance Survey.