The chancel retains its original Norman plan.
EXTERIOR The nave is Perpendicular, but the chancel retains evidence of its Norman origins.
The N porch has a plain parapet, with a chamfered outer opening and a double chamfered N door in a square frame with carved spandrels.
There are C12 angle shafts on the NE and SE corners, indicating that the original C12 chancel has not been lengthened.
the lower section is closed by a C17 screen.
The chancel roof is C19, a boarded wagon rood divided into panels by moulded ribs with a carved, embattled wall plate.
Screen enclosing the E end of the S aisle is largely C20, but the top beam is early C17.
C17 panelled screen closing the tower arch with a balustraded gallery.
C20 communion rail with turned balusters in a late C17 style.
Some interesting stained glass, including fragments of medieval glass reset in the SE chapel and in the N aisle.
Fine, painted armourial glass of 1741 records the beautification of the church by James Vernon, Esq., Lord of the Manor.
Early C20 glass in the N aisle, and E window by Harry Harvey of York, 1958.
Medieval graffiti has been whitewashed over.
Margery Gedding, and another of Thomas Underhill and Anne, his wife c.1530.
C20 monument to Florence Vestey, a large oval in alabaster with coloured metal arms at the top and a dove in polished aluminium in the SE chapel, and as a monument to Ronald Vestey, a small sculpture of a shepherd and his sheep on a wall bracket by Dame Elisabeth Frink , dated 1990.
HISTORY The earliest fabric is the C12 chancel.
The core of the nave is probably also C12
it was wholly remodelled in the C15 with the addition of aisles and a tower.
Unusually, the Norman chancel remained unextended, although the rest of the church has been rebuilt.
In the post-medieval period the church was refurnished by James Vernon, Lord of the Manor, in1741.
SOURCES Cautley, H M, Suffolk Churches , 357 Mortlock, D P, The Popular Guide to Suffolk Churches, I: West Suffolk , 87-88 Pevsner, N, rev. E Radcliffe, The Buildings of England: Suffolk , 237 REASONS FOR DESIGNATION The church of All Saints, Great Thurlow, St Edmundsbury is designated at Grade II* for the following principal reasons: * Excellent medieval fabric mostly of the C15 but including the high survival of an unextended Norman chancel. * Excellent fittings, including a very fine C12 font, good monuments of the C15-C20, and interesting glass including a fine C18 painted window.