Elslack (Olenacum) Roman Fort

Flavian Auxiliary Fort (AD 69–96)

This site has a Flavian foundation and its continued use through Hadrianic and Antonine times is shown by samian ware from both these periods. The fort was replaced in stone c.343AD and occupation is confirmed in coins and pottery dating to 360-370 and other pottery remains of the late-fourth century. Given the sparse pottery evidence, the fort may have been abandoned during the second century, also for a substantial part of the third.

The Flavian Infantry Fort

The original fort was square, with sides measuring 345 feet within the ramparts, giving an area of 2¾ acres for occupation. The clay rampart was laid on a foundation of stone, between 16 and 18 feet wide. A double-ditch 24 feet wide was separated from the rampart by a narrow berm, between 2 to 3 feet wide; the inner ditch was interrupted in front of each of the four gateways, while the outer ditch was continuous. First century pottery found within the defences, and a close resemblance to the fort at Ribchester in layout and construction, supports a Flavian foundation date. The internal area is just sufficient to house an auxiliary infantry cohort consisting of around four to five-hundred soldiers.

The Second-Century Cavalry Fort

The original Flavian fort was levelled in the second century and replaced on the same site by another, larger establishment. The new fort was a rectangle measuring 603 feet by 406 feet (184 x 124 m) outside the ramparts, which consisted of a clay bank revetted at the front by a stone wall 8 ft (2.4 m) wide; the enclosed area was about 5½ acres (c.2.3 ha). The original infantry garrison were replaced at this time by an auxiliary cavalry unit with a similar complement of troopers; the increased internal area of the fort was needed to accommodate not men, but horses.

No buildings were found in the interior of either fort, indicating either that none were present, which is extremely unlikely, or they had been constructed of timber and subsequently dismantled.

During excavations over the years a number of animal bones have been uncovered at Elslack, including those of Ox, Sheep, Pig, Red Deer and Hare; the latter two animals very likely being hunted and killed for sport, the others domesticated.

The Garrison Units

Ala Primae Herculaea – The First Herculean Wing

Praefectus alae primae Herculeae, Olenaco

“The Prefect of the First Herculean Wing at Olenacum

(Notitia Dignitatum xl.55; 4th/5th C.)

Unfortunately, the R.I.B. contains no entries on stone for Elslack, and the only known garrison unit is the Ala Primae Herculaea, who are attested at the Olenacum fort towards the end of the fourth century in the Notitia Dignitatum (vide supra).

Classical References to Olenacum

The first classical reference work which mentions the name of the fort at Elslack is the mid-second century geographical treatise by Claudius Ptolemaeus which attributes nine settlements to the Brigantes tribe of northern-England. Among these towns is the entry Olicana, which appears between Rigodunum (Castleshaw, Greater Manchester) and Eburacum (York, North Yorkshire). This Olicana entry has been equated with the fort here at Elslack.

The 4th/5th century Notitia Dignitatum also contains a similar entry Olenaco, which appears between records for Bremetenacum (Ribchester, Lancashire) and Virosidum (Brough by Bainbridge, North Yorkshire). The Olenaco item appears among the military units “at the disposal of the right honourable Duke of the Britains”, and somewhat strangely, under the sub-heading “the route along the line of the Wall”, meaning the Hadrianic fortifications across the north of England, although Hadrian’s Wall itself lies over 70 miles to the north. The full Notitia entry is given below.

References for Olenacum

  • The Archaeology of Roman Britain by R.G. Collingwood (Methuen, London, 1930);
  • The Roman Military Diet by R.W. Davies, in Britannia ii (1971) pp.122-142.

Map References for Olenacum

NGRef: SD9249 OSMap: LR103

Roman Roads near Olenacvm

WSW (19) to Bremetenacvm (Ribchester, Lancashire) E (13) to Ilkley (Ilkley, West Yorkshire)

Sites near Elslack (Olenacum) Roman Fort