Taff flows into Cardiff Bay, an artificial lake created by the construction of the Cardiff Bay Barrage in the 1990s, before flowing into the Severn Estuary. "Taffy" as a pejorative The derogatory term "Taffy" for a Welsh person is sometimes erroneously stated to have originated with the river. This may have given rise to a colloquial usage of the term "Taffy" or "Taffs" for people from the Mid Glamorgan Valleys (which form the Taff's northern reaches). The name actually originates as a corruption of the name Dafydd, with the Oxford English Dictionary describing the origin as "representing a supposed Welsh pronunciation of the given name Davy or David (Welsh Dafydd)". It was common for people in times of war to dehumanise an enemy by ascribing a singular name to them all. It is therefore an equivalent of other historic English pejoratives such as Paddy and Jock. The term is a common nickname within the British army, with Welsh individuals, units and especially the Welsh Guards referred to as "The Taffs". However, it has been reported that the guardsmen themselves never use that term. See also Pont-y-Cafnau, world's earliest surviving iron railway bridge Bibliography References External links Glamorgan-Gwent Archaeological Trust Merthyr Tydfil Features Rivers of Cardiff Rivers of Merthyr Tydfil County Borough Rivers of Rhondda Cynon Taf River navigations in the United Kingdom