Hadley Common was once part of a great expanse of land known as Enfield Chase. This was a favourite place of the Tudor monarchs for hunting. Local people, including the inhabitants of Hadley, were allowed to keep sheep and cows on the land, as well as take some firewood.
After the English Civil War some of the common was sold so that houses could be built. Mount House had been built by 1754 (since 1947 it has been St Martha's Convent School). The Chase was divided up between landowners after 1777, with the 240 acres in the parish of Monken Hadley becoming Hadley Common.
Anyone who owned more than three acres in Hadley was allowed what were called "stints", that is they were allowed to graze cattle on the new common. Unlike other parts of Enfield Chase, Hadley Common has remained mostly wooded.
A large ancient tree "Warwick's Oak" stood near the village until around 1941. It was supposed to be where Earl Warwick was killed during the Battle of Barnet, but this is probably a local legend.
Houses were built just below the common by the 16th century. The house next to Hurst Cottage is thought to be Tudor in origin. Most however were built during the 18th century. Folly Farm had fun fairs during the summer until 1939.