Williams was one of the first players brought in under Gordon Strachan. Saints defence desperately needed some cover after Dean Richards departure.
Williams had been in Coventry's relegation side, and a number of fans were concerned that he would be a poor signing.
They were all proved utterly wrong and Williams put in many impressive, solid displays.
The arrival of Michael Svensson put Paul down the pecking order once again. His services haven't been required too often as the first choice pair have remained fit.
The arrival of Danny Higginbotham pretty much ended Paul's chances of getting back into the first team, and it's good to see him start a fresh challenge elsewhere.
In Paul, Stoke now have a very determined, committed player who will undoubtedly improve their side.