In medieval times much of the Parish was moor or common land, with Gibbes Moor to the north-west and Harefield Moor and Cow Moor to the south-west. Harefield Common lay to the northeast and Uxbridge common intruded in the south. Even at the time of the 1813 enclosures there were still around 650 acres of moor and commonland in the Parish. The only through-road had been Harefield Lane (now Breakspear Road) from Uxbridge to Rickmansworth. A number of other roads existed, such as Harvil Road but they led only to farms. With the enclosures came road changes, among others Harvil Road was extended to Uxbridge and Springwell Lane to Rickmansworth. It was at this time that Moorhall Road was built to Denham.

In the early 18th century the village had four Inns, the Kings Arms and the White Horse among them. The Kings Arms has the remains of a 15th century house within it and the White Horse dates from the 16th century. By the 1870's there were five Public Houses and nine Beer Houses, by which time the population had grown to around 1500.

There was once in Harefield a grand Mansion, situated by the church. It was the home of the Lords of the Manor since ancient times and in the last year of her reign Queen Elizabeth I spent 2 days visiting the then Lord, Sir Thomas Egerton, and his wife Alice, later the Countess of Derby. It is said in Milton's biography by Masson that here William Shakespeare's Othello was performed in public for the first time by Burbidge's Players, who were richly rewarded by being paid £10, and Shakespeare would surely have been there for the first performance. There is some dispute over this claim, based on some skullduggery in Sir Thomas's accounts, but I prefer to still believe the story. The 2 day stay cost the Sir Thomas and others £4000, an enormous sum, worth £574,000 at todays valuation based on the retail price index. This was about the last occaision royalty imposed themselves on the aristocracy in this fashion as the costs involved were coming close to bankrupting the hosts. The Countess of Derby died in 1637, but not before endowing the village with the Almshouses on Church Hill in 1636. The mansion burnt down in 1660 and although rebuilt as a smaller house was finally demolished around 1814.

Although the existing St. Mary's church was built in the 12th century and much altered ever since, it is believed to have been built on the site of a Saxon church. Among other things the Countess of Derby's (d.1637) fine monument and the collection of medieval brasses make the Church one of the most visited in Middlesex and of national importance. There is also the largest ANZAC War Graves cemetary outside Australia and New Zealand of the soldiers who died from their wounds while being treated at the newley established Harefield Hospital. The village continues to have strong links with these countries.

The building the gallery occupies was once an old bakery and the enormous old brick and cast iron oven is still in situ. Bread was most likely baked in a building on this site or in the very near vicinity since Saxon times as an old Saxon bread oven was found while digging the foundations for a house just yards behind the gallery and a Saxon well lies under the car park. The present building, which is listed Grade II, was erected around 1800 and seems to have been built around the pre-existing oven. The premises have been used for various things, Post Office, Drapers, Video Shop and now a gallery among them, but it still retains many of the original features.