In 1936, Anthony Lowther, an archaeologist and member of the Society, was invited to investigate a suspected Roman mausoleum or temple site within the then Rothamsted Experimental Station. His findings eventually led to the mausoleum becoming a Scheduled Monument. In this article, Lexi Diggins considers the context and possible significance of the structure.
Iron Age Britain in 100 BC – a sophisticated tribal culture
We know that, in the decades immediately before the Roman occupation (by 100 BC), Iron Age Britain possessed a tribal culture with a higher level of sophistication than classical writers at the time suggested. Roman writers often dismissed British tribes as barbarians. However, there is evidence to suggest the British tribes had been trading with the Roman Empire, selling arable crops, animal hides and slaves for olive oil and wine long before any official Roman conquest.
These tribes lived in settlements, working as farmers, traders, warriors and craftspeople. They included wealthy individuals, many of whom were talented artists making beautiful decorative objects, such as bronze mirrors that were coveted across the Roman Empire.
Their houses were made from wood and thatch and now only post holes remain in the archaeological record as evidence of their former homes. However, their culture is visible in terms of ditches, pottery, weapons, decorative objects and coins.
What was local land use like?
There is ample evidence locally for the existence of these people in the area around Rothamsted. In the late 19th century a high status iron age burial was discovered south east of Harpenden Railway Station.  The finds demonstrated incredible workmanship.
There is evidence that, by the late Iron Age, the land in this area had been cleared, predominantly for growing arable crops and for grazing cattle and sheep. This includes bio-archaeological evidence of the types of crops and animals being cultivated and reared in this period. As Rosalind Niblett noted ‘..cereal crops were clearly grown but environmental evidence has demonstrated the importance of pastoral farming in the area…’ . We also know that Tacitus and Caesar wrote about cattle and horses being kept and there were pig bones found in excavations at Verulamium.
Late Iron Age and Roman settlements and trackways
This site was not isolated in the late Iron Age and Roman period; in fact, it was surrounded albeit at a little distance by active sites, such as Watling Street, the Roman agricultural villas at Turners Hall and Harpendenbury, the Temple site at Friars Wash and of course the third largest Roman settlement in Britain, Verulamium. Many of these sites also evidence late Iron Age activity or construction, in particular Iron Age ditches.
Two trackways in the area used in the Iron Age were later adapted and improved by the Romans – one running from Coldharbour (east of the River Lea) to Bylands on Watling Street near Redbourn; the other from Coles Lane/Dark Lane, across Harpenden common to Redbournbury. 
Lowther’s excavations in 1936-37
In 1936, the Director of the Rothamsted Experimental Station, E. J. Russell, invited Anthony Lowther, an archaeologist and Arc & Arc member, along with James Broad and Denis Wilson to excavate the site, known locally as Collye’s Grove. Lowther begins his report in 1937 by explaining that ‘The existence at Rothamsted of certain foundations, and of what were believed to be Roman pavements, has been known locally for many years…’. 
The area where the Mausoleum stands was said to have been a wooded copse thus linking the name ‘Collye’s grove’ with the topology of the area. We also know that place names often have historical origins. In this instance there is a connection between the Latin name for a sacred grove ‘nemus’ which indicates a spiritual place and Collye’s grove perhaps being used as a site for Iron Age worship or burials but most definitely being used as the site for an early British Roman burial ground and Mausoleum .
Interestingly, on a 1623 map of the Manor Estate, there is a small wooded area indicated where the trees seem to have been growing in a circle, unlike any of the other wooded areas described on the map which are either growing in strips to indicate boundaries or are larger woods. When compared with a modern map of the same area this ‘grove of trees’ appears to be where the Mausoleum ruins are situated and in Lowther’s report he also noted the same thing and posited that it may have been left free from cultivation due to the fact that there may have been more of a monument visible above ground in the 17th Century than there is today. 
While Russell was very interested in the history and use of the land, he was keen to ensure that Lowther did not over-excavate as he felt that less invasive archaeological techniques would be available in the future. How right he was.
A walled cemetery
Nevertheless, even within these constraints, Lowther was able to document some significant features. During investigations during the 1936 and 1937 seasons, he found that the mausoleum was set within a square walled precinct of some 30 m2. The site was bounded on three sides by a 0.8 m2 wide wall and berm, with the exception of the south-east side. An entrance way through the walled precinct was indicated by Lowther uncovering mortar remnants on the south-east side of the precinct walls, and there was evidence of a trackway leading to the entrance.
In his own words he records that:
The absence of the ditch on the fourth, or south-east side, suggests that the entrance was on this side. This suggestion was strengthened by the finding of two patches of mortar, each approximately eighteen inches square, on the surviving upper surface of the wall, at a distance of four feet apart, almost in the centre of this side of the enclosure. They suggest that there was a doorway here, with stone- or tile-built jambs set in mortar. A layer of broken bricks led to this point, and had probably been part of a road or pathway leading to the site. It may be conjectured from this that further structures await discovery to the south-east of the present site’
Within the precinct, two cremations were found dating respectively from 100-125 AD and the second century AD. These yielded finds of Castor and Samian ware, including flagons, dishes and a large pot. We know that at the approximate time of these burials, high status villas with mosaics and fresco walls were being built at Verulamium and at Friars Wash dating from a similar period there were high status finds such as Samian ware and a brooch from Gaul.
A tall mausoleum containing an almost life size statue
At the centre of the precinct stood a mausoleum with a diameter of 5.5 m2. On the basis of the 1.5 m2 deep foundations, the height of the structure was estimated at 6 m, and tiles found at the site indicate that it had once had a tiled roof. It would have stood out in the slightly raised landscape. The entrance to the mausoleum cella structure faced north east, and was flanked by two stone pillasters. Fragments of a draped statue made of limestone were found by Lowther. He estimated the figure to have been almost lifelike in stature and it would have stood on a plinth inside the cella.
In addition, an Iron Age ditch about 0.7m wide was found at the Mausoleum. That this ditch was already silted up when the mausoleum was built was demonstrated by the fact that the foundations of the western arc were cut into its fill. 
Possible significance of the structure
As a result of Lowther’s findings, the mausoleum was listed as a scheduled monument in 1938 and this status was confirmed under the Ancient Monuments and Archaeological Areas Act 1979 following a non-invasive survey by English Heritage in 1998.
As English Heritage put it when writing about another mausoleum at Stone-by-Faversham in Kent;
Romano-British mausolea are rare nationally. Known examples are widely dispersed with the main concentration in the south east, particularly in Kent. Mausolea are not found in Wales or Scotland but are common in the rest of Europe. Because of their rarity and their importance in providing information on Romano-British burial practice for persons of high status and on demographic and social organisation, all examples with surviving archaeological potential are considered nationally important. 
These buildings vary in ground-plan: square examples tend to be more common, but hexagonal forms are also known, for example at Colchester. The Romans called these funerary constructions monumentum, and they were according to English Heritage ‘physical embodiments of the need to perpetuate the memory of the high-status people who built them’. Rather than meeting the spiritual needs of a local population, they represent testimonies to the successful acculturation of those Romano-British elites who wished to create a lasting memory by way of a monumental family tomb and burial ground.
Lowther thought the Mausoleum was a Romano-Celtic temple. He had previously been excavating a temple site at Verulamium and went on to excavate other temple sites around Britain. Also, there weren’t as many Mausoleum sites in the archaeological record as there are today and English Heritage state that: ‘Romano-Celtic temples and mausolea share a relatively similar basic plan – a squared wall (ambulatory or precinct) enclosing a smaller structure usually known as the cella’ 
Holbrook, McSloy and Evans mention the Rothamsted precinct and burial ground as being one of the largest Roman walled burial grounds in Britain. This may be significant in a way that is not understood yet without further survey of the site. 
We know that Roman Governors like Gnaeus Julius Agricola, governor of Britain from 77-84 AD (about 20 years before our first cremation burial) encouraged the construction of Roman buildings by the local population and he was mentioned on the Titus dedication slab of the Forum Basilica at Verulamium as translated by Sheppard Frere and listed in the Roman Inscriptions of Britain website:
For the Emperor Titus Caesar Vespasian Augustus, son of the deified Vespasian, Pontifex Maximus, in the ninth year of tribunician power, acclaimed Imperator fifteen times, having been consul seven times, designated consul for an eighth time, censor, Father of the Fatherland, and to Caesar Domitian, son of the deified Vespasian, having been consul six times, designated consul for a seventh term, Prince of Youth, and member of all the priestly brotherhoods, when Gnaeus Julius Agricola was legate of the emperor with pro-praetorian power, the Verulamium basilica was adorned. 
Could his encouragement have influenced the building of the Mausoleum? Particularly the Tower style? The governor was born in Frejus, modern day South East France, then Gaul, where these Tower Mausoleums were a popular Roman design.
What questions remain?
Who built the Mausoleum and why? Based on the tower design, could it be a Roman citizen from Southern Gaul or Spain? Or A Romano-British high status individual who wished to convey that he/she had been fully assimilated into the Roman world and had visited either Gaul or Spain and seen these tombs? Perhaps then a member of the military who might have had the opportunity to travel on campaign?
Other mausoleums in Britain were built next to villas, grain stores and temples – for example, at two sites in Kent and one in Northampton. It may be worth considering whether or not this mausoleum is likely to have sat alone in the landscape.
I have in the last 10 years heard there were mosaic fragments found in the gardens of two Rothamsted staff cottages situated near the Mausoleum. Google Earth in some dry years shows rectangular outlines in the fields nearby. Could these be evidence of other structures and was this site part of a larger rural working estate? The Manor house nearby has Anglo-Saxon origins; could there have been earlier occupation there too?
What happened to the rest of the Mausoleum masonry? Was it removed for re-use in other local buildings at a later period? This has happened at other sites in Britain. Much of Verulamium ended up as building material for St Albans Abbey.
Is further investigation warranted?
Russell and Lowther left the site in 1937 no doubt hoping it might be excavated using less invasive techniques in the future . The English Heritage Survey in 1997 (see box below) suggests that the site merits further archaeological survey work to determine whether there are further burials and whether there are other structures within or outside the precinct walls and cella.
The Romano-British cemetery at Rothamsted is a rare example of an enclosed burial ground thought to have been constructed for the exclusive use of a high status family during the 2nd century AD. Limited archaeological investigations have demonstrated the ground plan of the cemetery and the central mausoleum but have left most of the enclosed area undisturbed. The structures revealed by the excavation have been preserved above and below ground. Significant archaeological deposits, including further funerary remains, will be retained within the unexcavated cemetery area. These will provide additional evidence relating to the dating and period of use of the cemetery and to the religious beliefs and practices of the people interred here. Environmental evidence preserved within these features may illustrate the nature of the landscape in which the monument was set. The site is known to have been used during the Late Iron Age, and the undisturbed portions of the cemetery may contain further features from this period which will illuminate its function prior to the Roman occupation. 
I agree that further archaeological survey work would be worthwhile, both to determine whether there are further burials, and whether there are other structures within or outside the precinct walls and cella.
Dependant on what is found it may then be possible to conduct limited excavation with great care. Modern advances in archaeological techniques could uncover more about who lived, worked and was buried in and around the site, and how the wider landscape was shaped by these people, both late iron age, Roman and Romano-British people and how long these people used the site.
Chalk soil is alkaline and preserves bone and teeth, so if the land is as I’ve been told chalky in places then it could be very revealing if we found inhumations. We could establish where individuals came from, their diet, overall health, age at death and how they died.
It may be that as with other local sites, that the Mausoleum was used later into the 3rd and 4th centuries AD and was active earlier in the Iron Age but we are yet to establish this in the archaeological record, for now based on the cremation burials we have two dates of 100-125 AD and 2nd century AD
In the meantime, I’m not sure that knowing whether the site is a family Mausoleum or a Temple is the most important question to debate. What matters is keeping an open mind and being able to add to the archaeological record, whilst also giving the local community an opportunity to understand more about who came before and how they lived. It’s reassuring on a very human level to think that there is a continuum of local occupation and land use on a site that is still being farmed today.
 Les Casey. Iron Age burial in Harpenden – Pre-Roman settlements in the Lea valley at Batford. Harpenden History Society website [‘HHS website’]
 Verulamium: The Roman City of St Albans by Rosalind Niblett. Stroud: The History Press (2010)
 Ibid, HHS website
 p1 Report on the Excavation of the Roman at Rothamsted Experimental Station, Harpenden A. W. G. Lowther, FSA [‘Lowther report’]
 Dr Kelly A. Kilpatrick from the Institute for Name-Studies, University of Nottingham explains that ‘The place-name Nemorensis Lacus, the Classical name of Lake Nemi, preserves the Latin term nemus ‘sacred grove’ (nemorensis being a Latin adjective of locality formed from nemus plus the suffix –ensis.). Latin nemus is a cognate of Celtic nemeton (‘sanctuary’ and often interpreted as ‘sacred grove’), an early term used to denote sacred space. The term nemeton is attested in various forms in the Celtic languages (historical and modern).’
 p8, Lowther report.
 p8, Lowther report
 p20, Lowther report
 A Romano-British mausoleum, an associated Romano-British building and a parish church at Stone-by-Faversham, Historic England website, accessed 16 September 2021
 Rothamsted Romano-British cemetery, Historic England website, accessed 6 September 2021 [‘HE website’]
 Neil Holbrook, E.R. McSloy and Derek Evans,‘Excavations and Observations in Roman Cirencester 1998-2007, Part 04 6 [of?] ‘The Western Cemetery Excavation and Watching Brief along Old Tetbury Road, 2004-6
 Translation from Roman Inscriptions of Britain
 Historic England report https://historicengland.org.uk/listing/the-list/list-entry/1018377