I'm a little confused, too. Awhile back I found some information pinpointing a genetic bottleneck for humanity at between 100,000 and 200,000 years ago. At this time, the human race was reduced to less than 20,000 individuals in eastern Africa. Now, it is conceivable that the folks living in England at this time were not modern humans, but Homo Erectus, the precursor of both Homo Sapien and Homo Neanderthalensis.
Homo heidelbergensis — sometimes called Homo rhodesiensis — is an extinct species of the genus Homo which lived in Africa, Europe and western Asia from at least 600,000 years ago, and may date back 1,300,000 years. First discovered near Heidelberg in Germany in 1907, it was described and named by Otto Schoetensack It survived until about 200,000 to 250,000 years ago. Its brain was nearly as large as that of a modern Homo sapiens.
Neanderthals, Denisovans, and modern humans (H. s. sapiens) are all descended from H. heidelbergensis.
East Anglia's only a few hundred miles from Heidelberg.