Uxendon, first recorded in a transaction concerning Hugh of Woxindon in 1257, was a small settlement on the western slopes of Barn Hill. The first part of the name is the same as that in the name Uxbridge and stems either from the Wixan, a 7th century Anglo-Saxon tribe, or from the Celtic for 'water'. The second part is the Old English for
hill.

Medieval Uxendon was very small, but in the 14th or 15th centuries some local people, including the Uxendon family, moved south to form another small community at Forty Green,
where the Sudbury to Kingsbury road crossed the Lidding at Forty Bridge. This settlement was known as Uxendon Forty, Wembley Forty or Preston Forty. The farm at Forty Green was at first called Pargrave's, and later South Forty Farm.

Uxendon became a submanor under the authority of Harrow Manor Court.

Richard Brembre, a grocer and Lord Mayor of London, lived at Uxendon. In 1388 he executed 22 prisoners without trial and was later himself executed for this crime. In 1516 the Bellamy family acquired Uxendon through marriage. They remained staunchly Roman Catholic after the Reformation and sheltered Catholic priests. In 1586 Anthony Babington, a principal conspirator in the Babington plot against Elizabeth I, was arrested on their property.

In 1592 Elizabeth's security services tracked the fugitive Jesuit Robert Southwell to Uxendon. As a result of these arrests the Bellamys suffered considerably in the final years of the 16th century. By 1608 their land was in the hands of the Page family, who had become the leading landowners in the Wembley area.

The Bellamys had already enclosed a small amount of open land. The Pages continued this process throughout the 17th century. In 1655 enclosure of open fields by Richard Page led to changes in the routing of the road east of Preston. This enclosure by the Pages encouraged the general move from arable to meadow in the area in the 18th century.

Nonetheless a significant amount of common land remained to be enclosed at the time of the Enclosure Act of 1803.

By 1732 a new farm, Barn Hill Farm, existed on the summit of Barn Hill. It was no longer there by 1850 and had probably gone by the late 18th century, when Richard Page began building a folly on Barn Hill as part of his improvements at Wembley Park. The folly was still standing in 1820.

In 1829 many of the Page family lands, including Uxendon, went to Henry Young (d. 1869), the junior partner of the Page's solicitor. There is good reason to suspect that Young obtained the lands fraudulently. In the decades that followed Young's death numerous persons turned up claiming the ‘Page millions’, but no-one was successful.

The district did not change significantly in the 19th century. This was due to an agricultural depression after the Napoleonic Wars and London's growing need for hay; both Uxendon and Forty farms had converted to hay farming by 1852. The depression also led to an outbreak of violence in the area around 1828, when desperate agricultural labourers burnt haystacks and threatened local landowners, including the relatively benevolent Lord Northwick.

64 people lived in Preston in 1831 and 57 in 1851. In the same year Uxendon Farm housed 13 people and Forty Farm 10, while three more lived at the top of 302-foot high Barn Hill.In the mid-19th century Uxendon was the venue for steeplechases and well known for its 'sensational water jump', while Forty Farm was famous for horses.

The Metropolitan Railway was built in 1880. The railway had no effect on development, even after the opening of Wembley Park station in 1894. In 1896 the suggestion that a station should be built serving Preston was rejected because the local population was so small. Indeed even in the early 20th century the area was entirely rural, and the
Wealdstone Brook could be described as "one of the most perfect little streams anywhere, abounding in dace and roach."

By 1900 Uxendon Farm had become a shooting ground (the Lancaster Shooting Club). When the Olympic Games were held in London in 1908 the ground was sufficiently important to be
used for Olympic clay pigeon shooting. Pressure from the shooting club, which was a two mile walk from the nearest station, played a part in the opening of Preston Road Halt in May 1908.

Some houses had already been built at Uxendon by 1930. Then in 1932 Uxendon Farm, which was in a terrible condition, was destroyed to make way for the Metropolitan Railway extension from Wembley to Stanmore (later the Bakerloo and today the Jubilee Line). In the years that followed the whole of Uxendon was developed except for Barn Hill Open Space, which had been purchased by the Council from the owners of Preston Farm in 1927.