Northern Gaul (Armorica, now known as Brittany). However, after Armorica was conquered by Julius Caesar in 56 BC, the trade dried up; the Romans re-arranged trade with Britain to the profit of their allies, the Trinovantes, in Essex. The next century or so until the Roman conquest saw a long drawn-out period of economic retrenchment in Dorset, in parallel with a rising population and a decline in soil quality (much of it had been in cultivation for 4,000 years). By the time of the Roman Conquest, it is likely that a combination of overpopulation and impoverishment of the soil left many people starving, to which bone analysis of skeletons from Bere Regis bears witness; several of the skeletons present ample evidence of numerous distinct episodes of severe malnourishment during childhood. The Romans record the name of the native British tribe that lived in Dorset as the Durotriges, who were also the tribe of much of Somerset and possibly the New Forest. Sometimes translated as "water dwellers", this name could mean that they were seafarers, but is more likely a reference to the marshy valley of the River Frome which they would have farmed. However, this etymology is unsound, based on the Welsh word dwr meaning water; however the earlier form of the word was dwfr, which suggests an Ancient British ancestor-word *dubro-, not *duro- (this form of the word is preserved in the place-name Dover). Another alternative is "fort-dwellers"; it is known that the Durotriges were still occupying their hillforts at the time of the Roman invasion in 43 AD, whereas in most other parts of Britain they had been abandoned around 100 BC. There is also a Cornish word dur meaning "land" or "earth"; hence the Durotriges might also be "land-dwellers", referring to their already important farming tradition: it is known that they were exporting grain to the Roman Empire in large quantities already by the first century BC. The etymology of the first element is thus far from certain, although the second element definitely means "dwellers" (Cornish tre, "town", tregez "have lived"; Welsh tref "town"). Roman The Romans landed in Dorset at Poole Harbour and the Fleet and moved inland, while other groups travelled west from Old Sarum and Winchester. At Abbotsbury on the Fleet the Romans quickly took the hill fort, Abbotsbury Castle, bloodlessly before moving on to Maiden Castle. There is some evidence of a struggle