The churchyard was closed in 1859, by an Order in Council of Queen Victoria. It includes many fine 18th Century headstones, and a survey has been done recently, to ensure that a full record of gravestones and memorials be kept. The splendid yew tree avenue can be assumed to date from 1500, probably at the same time as the FitzAlan beam, and is the finest and oldest in England.
The Doomsday Survey of 1086 recorded two churches under the Manor of Warbling ton (which was then included in the Manor of Westbourne) and since only one ancient church is now known in the neighbouring parish of Warblington-with-Emsworth it is likely that our building was the second ancient foundation. Additional evidence for this comes from two sources:
1) By 1071 Roger de Montgomery had the right to hold a Fair at Westbourne on 29th August, an obscure Feast day in honour of the Beheading of St. John the Baptist. Such Fairs were generally associated with the Church, so it seems probable that there was already a church in Westbourne with this, very unusual, dedication.
2) During Victorian restoration work, the then Rector (the Revd. J. H. Sperling) reported that below the present flooring he saw “large square bases of early Norman pillars, on which the later pillars had been built”. Such supporting evidence suggests that the original church was built in 11th Century or before, although the main architectural evidence is from 13th-16th Centuries, with heavy restoration in 19th and modern additions in 20th.