The D-prefix was introduced in 1899 and was heavily used throughout the 1902–1922 period for the company's famous "Series Ware" and vibrant transferware. D1138 to D1495 1910: D3230 to D3374 1922: Patterns crested into the D4000s

These patterns typically relied on heavy gold encrusting, delicate hand-painted floral sprays, and intricate Gilded Age aesthetics aimed at high-end dining. Doulton series and patterns numbers - The Old Stuff

For its luxurious fine bone china, Royal Doulton utilized the E-prefix from 1901 until roughly 1915. In 1916, it transitioned to the legendary H-prefix, which continued for decades.

Flow blue designs, the famous Indian Tree pattern, and early scenic landscapes like the Woodland and Haystacks collections. ☕ Bone China (E-Prefix & H-Prefix)