This was once a cruciform church but the transepts were demolished in the fourteenth or fifteenth century, leaving only their gable lines behind on the north and south walls of the tower, and the building today consists of a nave, central tower and chancel, with aisles in Perpendicular style running alongside the nave and tower, to join up with short thirteenth/early fourteenth century chapels beside the chancel's western bay.  A windowless porch leads into the S aisle, a modern lean-to vestry continues the line of the N. chapel to the east, and a heavy rectangular stair turret rises at the northwest angle of the crossing, forming in its lower part, an entirely enclosed, detached structure within the present aisle.

 

The oldest work is represented by the lower parts of the crossing. The crossing arches (illustrated below left, from the west), although pointed and narrower to the north and south than the east and west, are Norman-Transitional:  three flat-chamfered orders comprising the arches themselves, are carried on massive capitals supported in turn by two orders of heavy shafts - the outer, circular, and the inner, keeled.  The double-flat-chamfered arch from the chancel to the S. chapel and the triple-flat-chamfered arch to the N. chapel, cannot be much later, implying the chapels soon followed the realisation of the original plan.  Perhaps contemporary with these, albeit of more elaborate design, is the arch from the former transept to the S. chapel, which,  although substantially renewed, carries dog-tooth and several rolls within its complex series of mouldings.  Immediately beyond, a renewed three-light chapel window with intersecting tracery, probably also witnesses the thirteenth century, while the E. window with reticulated tracery, appears to be an early fourteenth century replacement.  The only other window  in the church with this tracery is the renewed five-light chancel E. window, but a tomb canopy (or Easter sepulchre?), the two-bay sedilia, and the piscina, all recessed in the S. chapel S. wall, as well as a nodding canopied niche for a statuette, left (north) of the chapel E. window, are other Decorated features, as shown by their ogee arches, heavily ornamented with crockets.

 

To the west of the tower, in contrast, everything is Perpendicular, as also are the upper parts of the tower, including the bell-stage with its slightly depressed cusped Y-traceried bell-openings and the leaded spike behind the parapet.  The nave aisles are embattled and the bays divided externally by buttresses terminating in large crocketted pinnacles.  The three-light restored aisle windows have supermullioned tracery and split Ys beneath two-centred arches.  The nave is lit to the west by a four-light window with subarcuation of the lights in pairs and through-reticulation, above a doorway with two orders of side shafts supporting a complex series of mouldings round the arch, including a roll with a fillet and a series of waves and hollows.  The very short clerestory windows are three-light and square-headed, and positioned above the apices of four-bay nave arcades composed of double-flat-chamfered arches springing from tall, rather slender octagonal piers, with relatively  modest capitals, consistent with the fifteenth century.  (See the photograph of the N. arcade, above right.)

 

Most of the interest in the furnishings in the church, resides in the monuments in the N. chapel, the largest of which are dedicated to members of the Slingsby family.  The oldest and biggest of all commemorates Francis Slingsby (d. 1601) and his wife, Mary, whose larger-than-life effigies recline on a heavy tomb-chest, with their hands clasped in prayer.  The church guide (Arnold Kellett, Parish Church of St. John the Baptist, Knaresborough, Knaresborough, Friends of St. John's, 2011, p. 16)  ascribes the work to a certain Thomas Brown, who charged £13 for his labours.  Slightly later are two monuments which Pevsner states were ascribed by Mrs. Easdale to Epiphanius Evesham (The Buildings of England: Yorkshire West Riding, Harmondsworth, Penguin, 1967, p. 295), the first commemorating Sir Henry Slingsby (d. 1634), featuring Sir Henry standing between two columns with Ionic capitals, wrapped in a shroud and with an inscription in Latin, and the other, commemorating Sir William Slingsby (d. 1638), featuring a standing figure of the deceased, wearing a hat, boots and spurs, and leaning nonchalantly on his sword.  Finally, the church contains no woodwork of real consequence but two stained glass windows were attributed by Pevsner to Ford Maddox-Brown, set in the S. wall of the chancel and the W. wall of the S. aisle.  The latter (shown left) is the best and depicts six saints arranged in two tiers.