In 1829 a fairly modest villa designed by Robert Lugar was built at Betteshanger for Frederick E. Morrice. In 1850 Sir Walter James bought the estate and employed Anthony Salvin on some internal alterations to the house as well as new stables, a lodge, a village school for Northbourne and rebuilding Betteshanger church.
Sir Walter James was a devout man, he even taught at the local Sunday school. In 1853-4 he had Anthony Salvin completely rebuild St. Mary's church at Betteshanger in the Norman style, imitating the 12th century church at Barfreston. Sir Walter even helped with the work, carving some of the figurative stonework on the pulpit, he was described as 'a mason and carver of no mean ability'.
About 1856 he employed architect George Devey to undertake major additions and remodelling of the house. This was Devey's first major commission and established his reputation as well as creating the Old English country house style. He continued on the house at various times until his death in 1886.
Devey was one of the most prolific Victorian country house architects. His houses borrowed features from the local vernacular by using local materials and styles, for example at Betteshanger he first made use of Dutch gables which were originally introduced to east Kent by the settlers from the Low Countries in the late seventeenth century. The main house, as well as the various estate cottages and lodges, are characterised by tall chimney-stacks and a variety of building materials, ragstone, bath stone, flint, yellow brick, red brick and tiles.
His style was calculated to give the appearance of a house growing up gradually over the centuries. The 'medieval' James Tower gives the impression of ancestry in Betteshanger House because the stone work in the tower rise to an uneven height to give the illusion of a rebuilt ruin. There is also an 'Elizabethan' wing and an extensive patchwork of seventeenth century styles forming the main block which complete the complicated arrangement.
Devey worked on a number of other projects; he laid out the garden terraces of Betteshanger House, improved Betteshanger church and rectory, as well as the churches of Northbourne and Ham. At the Eastry workhouse he built a chapel and a cottage hospital on the outskirts of Eastry.
Sir Walter James and the Liberal Prime Minister William Gladstone were friends and Devey gained further work from some of the leading liberals of the time, including Lord Granville and the Duke of Sutherland.
George Devey was one of the first architects to photograph his buildings under construction as well as examples of buildings of other periods as an aid for his designs of mixed architectural styles. He was noted for his perspective drawings as he had studied under the watercolourist James Duffield Harding and so indeed had his patron, Sir Walter James. Devey's patrons tended to be like-minded people, artistic wealthy intellectuals. A later house by Devey, St Albans Court at Nonington, was built in 1875-8 for William Oxenden Hammond who was also an enthusiastic watercolourist and friend of the James family.
Additional work on the house and Stable Court was carried out in 1893-9 after Devey's death.
In 1936 the house became a preparatory school, now Northbourne Park School.
 - Robert Lugar, (1773? - 1855). He practiced principally as a domestic architect and he was the first to apply the ideas of Sir Uvedale Price and Humphrey Repton on picturesque landscaping to the house design.
 - Sir Walter James (1816-1893), He succeeded his grandfather as second baronet in 1829. In 1884 created Lord Northbourne, 1st Baron.
 - Anthony Salvin architect, (1799 - 1881). He specialized in country houses for the aristocracy in the style of a transitional phase of the Gothic Revival; a style he did not develop greatly over sixty years, and he never became an important church architect. He became an expert in medieval fortifications, and carried out restoration work on Windsor Castle, and the Jewel House at The Tower of London. He was involved in building and altering over 73 country houses. Salvin was elected a fellow of the Royal Institute of British Architects in 1836, became vice-president in 1839 and in 1863 the Institute conferred him it's gold medal.
 - Obituary of Lord Northbourne - 1st Baron, Deal Walmer and Sandwich Mercury
 - George Devey architect, (1820 - 1886). Other work in Kent includes Leicester Square cottages at Penhurst in 1850; Benenden parish school in 1861; Denne Hill in 1871-5; Hall Place at Leigh in 1871-6; Albans Court at Nonington in 1874-8.
 - William Ewart Gladstone (1809 - 1898), Liberal Prime Minister on four occasions between 1868 and 1894. Sir Walter James had been a liberal MP for Hull from 1837 to 1847, at a time when Gladstone was a Conservative.
 - James Duffield Harding (1798 - 1863), watercolourist and lithographer, exhibiting two drawings at the Royal Academy aged thirteen in 1810. He was skilled at rendering architectural and topographical views and was one of Englands first great artist-lithographers as well as an innovator and experimenter in the then recent art. In the 1820s, 30s and 40s he travelled extensively in Europe and produced books of his travels.
 - William Oxenden Hammond of Nonington (1817 - 1903).