The church was completely changed in the 14^th century. The tower arch, the chancel arch and the two, six bay arcades belong to this period. The south porch and priest’s door were also added at this time. In the late 15^th century the roofs were replaced; all are made of oak, with quite a high standard of workmanship. Also, the tower was raised to its current height. All this work must have made the building quite an impressive sight by the end of the century.

Very little is known of the interior of the church until the 19^th century. It can probably be assumed that various alterations in layout were made during the 17^th and 18^th century to take account of current Anglican thinking. It is definitely known that in 1841 the interior was reorganised. This reorganisation was somewhat of a compromise between modernisation and conservation, but in any case, this arrangement did not endure for long.

It is perhaps fortunate that Longstone is a bit of an out-of-the-way place, because this isolation staved off further alterations until 1872. Several other churches in the area suffered enthusiastic, but rather unsympathetic modernisation in the first half of the 19^th century. When Longstone’s turn came, in 1872, it seems to have been a more measured affair. The architect – R. N. Shaw - came personally recommended by a local family, and had a more sympathetic approach than many.

The work of 1872 found that the majority of the structure was sound, apart from the oak roofs. Most of work done on the structure was to implement an impressive steel structure to support the ailing roof timbers. This is so well done its existence is almost invisible to the eye. Some minor wall repairs were carried out, some windows replaced and some added and the majority of the internal woodwork replaced. The five-light arched window taking up the whole of the east wall of the building was added at this time. The addition of the stained glass to replace the plain followed the completion of building work.

Since the completion of the work in 1872, very little else has been done to the building. Electric light and a better heating system have been installed, and a new vestry added.

Much more information about the architecture and history of the church can be found in "St. Giles, Great Longstone". This is usually available in the church. The booklet is a compilation of material from many sources, edited by J. N. Tarn. Originally published in 1977, the 1997 second edition has been brought up to date with changes and some corrections made.