He also played Vernon Dursley in the `` Harry Potter '' films , Uncle Monty in `` Withnail and I '' , Henry Crabbe in `` Pie in the Sky '' , and King George II in '' '' .
Griffiths is mostly known for his roles as Harry Potter 's Uncle Vernon Dursley in the `` Harry Potter '' movie series , Uncle Monty in `` Withnail and I '' , Henry Crabbe in `` Pie in the Sky '' , and as King George II in '' '' .