320 million years ago, when the area was a river delta, sediments were laid down and eventually transformed into sandstone, here called Millstone Grit. Today, a layer of peat, which started to form about 5000 years ago, covers the rock. Before the peat formed, most of the moors were covered with a dense forest of pine, birch and oak.
The area was thinly populated in prehistoric times. It seems that, as animals recolonised the area after the last Ice Age, the area became a seasonal hunting ground for early humans. There were hunting settlements on the high ground by 7000BC Stone Age tools have been found at Pule Hill, Warcock Hill, Standedge and March Hill.
The Celtic tribe in this area when the Romans arrived, was the Brigantes. They occupied a huge area north of the Humber, though the area was very sparsely populated. The Brigantes were a powerful tribe and were ruled by Queen Cartimandua.
D Sykes, in his History of the Colne Valley, paints a highly fanciful picture of wild and independent hill people, indulging in Druidism and human sacrifice.
In 1881, a stone altar was found in Longwood, which read: To the Holy God of the Brigantes and to the Divinity of the Emperor, Titus Aurelius Quintus, by the decree of the Decunions has placed (this altar) and fulfilled his vow.