I have been writing, on behalf of Thatcham Historical Society, articles for a local magazine. So here is a copy of another one of the articles:
There was a market in Thatcham which is believed to originate between 1100 and 1135, perhaps earlier. At this time Thatcham was classed as a town and by 1304 was also borough. Thatcham had a rather successful market and apparently the envy of many surrounding settlements as in c.1160 the men of Newbury attacked the market. They overturned stalls and allegedly caused a pitched battle in the Broadway. The monks at Reading Abbey appeal to the king who issues a further charter directing that the monks be allowed to hold their Thatcham market without interference and forbids the men of Newbury to do any injury to it. By 1539 the market was recorded as being worth nothing and soon stopped.
The Market Cross, or Butter Cross, itself is believed to be 15th Century although it was pretty much gone by the early 19th Century.