Wear marks caused by opening and closing the visor are still visible, and at some point the helmet was repaired using a bronze sheet which was riveted across two splits.

This alloy was probably derived from melted-down scrap brass with a low zinc content, with which some tin had been added to improve the quality of the casting.

[2][4] Some of the fragments show traces of a white metal coating, indicating that the visor would originally have been tinned to give the appearance of silver.

[2] The helmet's creation can be dated to the late 2nd or early 3rd century from the use of a particular type of decorated rivet as well as some of its design features, such as its pierced eyes.

The finder, an unnamed metal detectorist in his 20s from Peterlee, County Durham, had been detecting with his father in two adjacent fields for some years but had previously only discovered some Roman coins and other small artefacts.

[5] Following the helmet's discovery, the area around the findspot was investigated in a project sponsored by the Tullie House Museum and Art Gallery and the Portable Antiquities Scheme.

[5] The finder discovered the helmet and visor buried together some 25 cm (10 in) below the surface,[2] at a site located on a ledge at the lower end of the settlement.

[2] No other artefacts were found at the time, but the subsequent Tullie House/PAS excavations at the findspot discovered a number of copper and iron objects, a bead and two Roman coins dating to 330–337.

[2] Although Christie's was asked to delay the restoration so that a full scientific examination could be carried out, this request was not granted and information about the helmet's burial may have been lost as a result.

[7] However, the British Museum was able to inspect the find during restoration and X-ray fluorescence spectrometry was carried out to determine the composition of the headpiece, visor and griffin.

Bradbury's restoration work took some 240 hours and involved the repair of cracks and holes using resin and cyanoacrylate ("Super Glue"), retouched to match the appearance of the surrounding material.

[3][4] The griffin ornament is unique, though it may parallel a lost "sphinx of bronze" that may originally have been attached to the crest of the Ribchester Helmet, discovered in Lancashire in 1796.

The headpiece is nearly unique; only one other example in the form of a Phrygian cap has been found, in a fragmentary state, at Ostrov in Romania, dated to the second half of the 2nd century AD.

Horses and riders wore lavishly decorated clothes, armour and plumes while performing feats of horsemanship and re-enacting historical and legendary battles, such as the wars of the Greeks and Trojans.

[2] According to the Roman writer Arrian: [T]hose of high rank or superior in horsemanship wear gilded helmets of iron or bronze to draw the attention of the spectators.

As the horses move forward, the slightest breeze adds to the beauty of these plumes.— Arrian, Ars Tactica 34[9]Combat gear was issued by and belonged to the Roman army, and had to be returned at the end of a wearer's service.

The Dutch historian Johan Nicolay has identified a "lifecycle" for Roman military equipment in which ex-soldiers took certain items home with them as a reminder of their service and occasionally disposed of them away from garrison sites as grave goods or votive offerings.

[10] The circumstances in which the Crosby Garret helmet was buried are still unclear, but the discoveries made by the post-discovery Tullie House/PAS excavations have provided much more detail about its context.

The discovery was publicly announced by Christie's in mid-September 2010; the helmet was the centrepiece of its 7 October auction catalogue, featuring on the cover and six more pages.

It was lent by its owner to the Royal Academy of Arts in London, and was put on display from 15 September to 9 December 2012 as part of an exhibition of bronzes.

[12] From 1 November 2013 until 26 January 2014 the helmet was on display at the Tullie House Museum and Art Gallery in Carlisle,[13] and a printed guide was produced for the occasion.