During this period Harringay emerged from the mist of prehistory as a thickly forested area of southern England. By 1750 most of the forest had been cleared for agriculture, although settlement was still sparse.
About 60 million years ago the area lay in a sea bed of clay, 180 metres deep in water. Once Britain’s land mass emerged from beneath the water, the area was part of the hinterland of the swamps and marshes of the Thames. Plenty of fossil evidence has been discovered that shows mammoths, hippos, hyenas and rhinoceros once roamed thereabouts. In the Ice Age, Harringay was at the edge of a huge glacial mass that reached as far south as Muswell Hill. There is evidence of both Stone Age and Bronze Age activity in the immediate vicinity; Stone Age implements, estimated as 200,000 years old, were unearthed in the Finsbury Park Area and near Stoke Newington. A 4,000-year-old bronze dagger, now in the possession of the British Museum, was found in Hornsey.
Prior to the Romans' arrival, Harringay was part of a large area covering Essex and Middlesex which was home to a Celtic tribe called Trinobantes. Led by Imanuentius at the time of the Roman invasion, they fought with the Iceni tribe under Boudica against the Romans in AD61. The two tribes lost, sustaining casualties in excess of 80,000. Whatever their record in battle, they were a well organised society. On his arrival Julius Caesar found an 'elaborate and well-organised tribal civilisation. Its population was exceedingly large and the ground thickly studded with homesteads'.
The Roman invasion of Britain started in the middle of the 1st century BC and drew Harringay into the wider world. With the Romans' main settlement just 5 miles to the south, there is good evidence that Green Lanes was established a major road to the north in Roman times. Of direct archaeological evidence of settlement in the vicinity at the time there is little. The only significant find was a hoard of 3rd and 4th century gold coins found between Hornsey and Muswell Hill in 1928.