ROMAN URBAN TOPOGRAPHY in Britain and the western Empire

Colchester: the mechanics of laying out a town Philip Crummy
The Roman colony at Colchester was not laid out on open
ground as a single planned entity, but was formed by
adapting a redundant legionary fortress (Fig 53; Crummy
1977; 1982a). The process of conversion was extensive and
involved considerable building work. The legionary defences
were filled in and a new street grid was set out on the
east side at a slightly different angle, so that it covered the
area of the legionary annexe and the eastern half of the
fortress. The via principalis and the north-south streets to
the west of it appear to have been retained for the colony.
The via sagularis was also kept, except on the east side of
the fortress where it was replaced by a new street built over
the levelled legionary defences. The area of the annexe
seems to have been given over partly, if not entirely, to
public buildings. Four are known here: the Temple of
Claudius, the theatre, and at least two others, one in insula
29 and another, perhaps a large basilica, in insula 30. The
last two buildings had pre-Boudican forerunners, discovered
and partly examined by Hull who felt that they were
both public in character (Hull 1960, 310, 316). According
to Hull, the building in insula 30 probably contained
columns 3ft (lm) wide which were covered with fluted
stucco. It is not certain if the theatre is the one referred to
by Tacitus when he wrote about the strange occurrences in
Colchester shortly before the Boudican revolt (Annals,
xiv.32). The remains of a pre-Boudican theatre may lie
underneath, although no trace of this was noted during the
small exploratory excavations of 1981 (Crummy 1982b).
At a recent excavation in Culver Street the pre-
Boudican remains proved most important (Rankov 1982,
371). On the east side of the via principalis were found the
corners of two large buildings whose size and position are
consistent with those of tribunes’ houses. They were
separated by a narrow, well-gravelled street c 6m across.
The walls were built of timber posts set in construction
trenches up to c lm deep. The buildings had been
demolished and an east-west street of the new grid was
laid on top on a slightly different alignment. Timberframed
houses were built along the frontages of the new
street and were destroyed in 60/l. In contrast to this
sequence, the centurial blocks, situated to the west of the
via principalis, survived until the revolt.
About two-thirds of the eighteen or so military buildings
recognized so far in Colchester were destroyed in the
fire. This fact, combined with the number of streets which
were reused, suggests that a substantial proportion of the
military buildings must have survived the change from
fortress to town. Probably there would have been insufficient
space within the former fortress for all the large
civic buildings which the first colonists required; the
defences were therefore levelled and the area of the annexe
was given over primarily to them. This would explain the
otherwise puzzling statement by Tacitus, ‘It seemed easy
to destroy the settlement; for it had no walls. That was a
matter which Roman commanders, thinking of amenities
78
rather than needs, had neglected’ (Annals, xiv.32). The
‘amenities’ must be the group of public buildings which,
as already explained, would only have been laid out after
the defences had been levelled. Excavations at Balkerne
Lane have confirmed Tacitus’s statement that the colony
was unprotected in 60, because it was found that houses
burnt in the revolt had been constructed over the levelled
military defences and that these defences were not
replaced until after the fire (Crummy 1977, 96).
The destruction of the military bank and ditch was a
mistake which was not repeated when, in the post-
Boudican period, other fortresses were converted into
towns. At Gloucester (Hurst 1972), Lincoln (Jones 1980),
and Exeter (Bidwell 1979; 1980) where much is now
known about their early development, the legionary
defences were retained and the towns were initially held
within the circuits of their military ramparts.
At Colchester, the fate of the principia is not known.
Perhaps it was retained in the colony to fulfil some civic
administrative purpose or perhaps it was demolished and
the via decumana and the via praetoria joined up to form a
continuous east-west street. The street to the west of the
via principalis was later to replace it as the main northsouth
street of the town. The date of this change is
unclear, but it probably occurred just after the Boudican
revolt when the colony was provided with its first defences
and gates.
The process of converting the fortress into a town may
have taken several years. The evidence for this comes from
three places: (i) the Temple of Claudius; (ii) the backfilling
of the legionary ditch; (iii) the theatre.
It has been argued that the Temple of Claudius could
not have been started until after the death of Claudius in
54 (Fishwick 1972). Since the insula containing the temple
is apparently the dominant feature of the eastern grid and
clearly an integral part of its layout, then either the grid
was set out no earlier than 54 or, before this date, the insula
contained only an altar as, for example, at Lyons and
Cologne.
The legionary defences at Balkerne Lane had been
much neglected before being levelled. Debris had been
tipped into the butt ends of the ditch, pits dug on its
western side, and at least one building, probably a
workshop, had been built up against the southern butt end
so that it encroached onto the main street. Since no
military commander would have tolerated such treatment
of his defences, the bank and ditch must have been intact
for some time after the evacuation of the garrison
(Crummy 1977, 76).
The western side of the theatre appears to overlie the
levelled defences of the fortress (Fig 53). Moreover, it is
not on the alignment of the eastern street grid as might be
expected, but shares the same alignment as the fortress.
These two facts seem to indicate that between the
destruction of the defences and the laying out of the