Encyclopaedia Cambrensis

The Encyclopaedia Cambrensis or Y Gwyddoniadur Cymreig was the most ambitious encyclopedia in the Welsh language. It was published in ten volumes between 1854 and 1879 by Thomas Gee on his press in the town of Denbigh, Gwasg Gee. The general editor was John Parry, Gee's brother in-law and lecturer at the College of Bala. It remains the largest paper publication in Welsh today.

The project cost for Gee was about £20,000 (equivalent to £2,600,000 in 2023).