When did Belleek start producing its famous parian ware?

Belleek’s parian ware story is closely tied to 1863. Multiple historical summaries of the pottery point to 1863 as the point when the pieces Belleek became famous for were first made, after earlier domestic wares and experimentation. For dating, this matters since the official first Belleek mark begins in 1863 and runs to 1891, aligning with the period collectors chase as “first mark” or “first black mark” territory.