This example is a King George IV brand earthenware whiskey decanter with original stopper.
Decanter stands 14.8cm tall, or 17.8cm when lid in place. It has a base diameter of 6.8cm, a rim diameter of 3.4cm, and is approximately 11cm wide.
Understamp dates this decanter circa 1922-1927. Impressed "Royal Doulton, Made in England