The half-crown was 2/6 (12½p in today’s money) and I think was withdrawn about 1970.
There was also a crown (5/- or 25p), but AFAIK this was never struck as a circulation coin in my lifetime – only as a commemorative coin for occasions such as the Silver Jubilee in 1977. They’re still legal tender to this day, but are probably worth considerably more than their face value.
Finally, there’s a new crown (a £5 coin!), but again, this has so far been struck only as a ceremonial coin, although it is legal tender. The way the economy is going, we’ll probably have circulation crowns before many more years have passed; there’s already a “Save Our Fivers” campaign aimed at preserving the £5 note.