"Send them to Coventry" - where does this phrase come from?

I have heard this phrase 3 times in the last week. Finally got round to looking up its origins. Meaning “to deliberately ostracise someone”, this phrase originates from a 17th century English Civil War punishment, when Coventry was a Parliamentary stronghold. The king's soldiers were so hated that Royalist prisoners were sent to Coventry, where it was felt they would be ignored.