Legge then joined Eric Higgs' research group at Cambridge investigating the early origins of agriculture, where he specialised in archaeofaunal analysis.
Legge was also involved in archaeological faunal analyses in Britain, Cyprus, Spain, Serbia, and Croatia, in each region seeking to follow the nature of animal domestication there.
At Grimes Graves in England, he studied the animal bones from two Bronze Age middens, where the inhabitants kept cattle, some sheep and a few pigs, and from these remains, he identified an intensive form of dairy husbandry.
This interpretation stimulated some controversy in 1981, though more recent work on milk residues in Neolithic and Bronze Age pottery shows that this form of husbandry was indeed widespread in European prehistory.
Legge was a Senior Fellow in the MacDonald Institute for Archeological Research at Cambridge, where he continued to work on material from Tell Abu Hureyra, and Tell el Amarna in Egypt (with Professor Barry Kemp ) until his death in February 2013.