Legend has it that a Roman - Brutus - had three sons between whom he divided his lands. His elder son, Locrinus, received the land between the rivers Humber and Severn, which he called Loegria. His second son, Albanactus, got the lands beyond the Humber, which took from him the name of Albania. The younger son, Camber, was bequeathed everything beyond the Severn, and is called after him "Cambria".
This legend was hugely prevalent throughout the 12th - 16th centuries, but came under serious attack in later times, and there now seems to be little documentary evidence to support it.
The name lives on however in much contemporary literature, and it is used in Geology to denote a geologic period existing between around 545 million years and 490 million years ago, now known as the Cambrian.
Cambria is also the name, or part of the name, of several other places: