digging through my nightstand 'thingy' box (contains broken watches,collar stays,cuff links,tie-pins , loose foreign coins etc.) I came across a £5 coin dated 1999/2000, must have got it on my last visit to the UK ......anyway nowhere on the coin does it say what it commemorates, so after a bit of digging I found this site
British Coins: Type Collecting - 5 Pounds
seems it's a millenium £5 coin , but what surprised me was that the British mint has been issuing them annually since 1996 , wonder if anyone is collecting them and has the full set for passing down to their children or grand-children