[1] The River Sem, from which the village takes its name,[2] forms part of the northern boundary of the parish.

In AD 955 King Eadwig granted land to Wilton Abbey, and Semley was probably part of that estate.

under Henry VIII's Dissolution of the Monasteries, the Abbey had to surrender its lands to the Crown, including the manor of Semley.

[2] In 1541 Henry VIII granted Semley to Sir Edward Bayntun and his wife Lady Isabel as part of his policy of re-allocated monastic land to his nobles.

Arundell gave the house in 1639 to Cecil Calvert, 2nd Baron Baltimore, proprietor of colonies in Maryland and Newfoundland.

[4] In 1935 the house was remodelled to designs by the architect T. Lawrence Dale, who reinstated the earlier hall and added a neighbouring room to enlarge it.

The bulk of Benett's acquisitions at Semley remained with his heirs until his grandson Vere Fane Benett-Stanford died in 1894 and his widow married Charles Thomas-Stanford in 1897.

This estate descended by the Marquess's daughter Octavia to her husband Sir Michael Shaw-Stewart, 7th Baronet.

After the death of Sir Michael in 1903 and Lady Octavia in 1921, their son Walter Richard Shaw-Stewart held about 850 acres (340 ha) at Semley.

[2][6] In 1976 the Diocese of Salisbury united St. Leonard's benefice with Sedgehill,[8] and in 1985 East Knoyle was added.

[9] In 1987 the church was recorded as Grade II listed,[10] along with the dwarf brick walls and decorative cast-iron railings on two sides of the churchyard.

Semley's pasture was mostly common land in the Middle Ages but about 500 acres (200 ha) were enclosed between 1599 and 1769.