Sir John Winter was born in about 1600, the son of Sir Edward Winter and Anne Somerset Winter. Edward Winter invested in the Forest of Dean's iron-making industry and his son John continued that tradition. In 1640 Sir John purchased all the mines, stone quarries and mineral rights in the Forest of Dean, which included all the rees and and woods growing there. He paid £10,000 initially with a further sum of £16,000 for those rights for six years. Soon after he had 15 furnaces and 20 forges across the area. He began fencing his lands, much to the rage of the local Foresters who depended on the grazing and the firewood to survive.

During the Civil War he was an ardent Royalist supporting King Charles I and fighting the Parliamentarians. In 1643 he heavily fortified his house, White Cross Manor, in Lydney. On at least two occasions in 1644 and 1645 Winter found himself cornered whilst up against the troops of Colonal Massey. Both times he escaped by boat on the River Wye.The tale of his escapes became exaggerated over time into a heroic leap from the cliffs on horseback, down 200' cliffs at Lancaut. This led to the cliffs being called Winter's Leap!

In April 1645, rather than to loose his fortified home to the Parliamentarians, he ordered it burned down!