Trimontium
- a later name of the city Philippopolis in Thrace, Plin. 4, 11, 18, § 41.
TRIMONTIUM (Τριμόντιον, Ptol. 2.3.8), a town of the Selgovae, in Britannia Barbara, probably near Longholm, in the neighbourhood of the Solway Frith. [ T. H. D.]
The Roman fort, which took its name from the triple peaks of the nearby Eildon Hills, lies on the E side of the village of Newstead, guarding the point at which the Roman road from York to the Forth crossed the Tweed.
Excavations in 1905-10 and 1947 disclosed that there were four superimposed forts. The earliest, built by Agricola ca. A.D. 80, covered 4.14 ha and was defended by a clay rampart, 6.9 m thick, and double ditches. Its outline was unusual, the rampart alignment being staggered at each of the four gates. Only one internal building, a timber-framed stable, is known, but it is possible that the garrison comprised two alae quingenariae. This fort was replaced in the late 80s by another, 5.7 ha in extent. The new rampart was 13.5 m thick and the single ditch over 4.8 m wide; the scale of the defenses reflect the fact that Trimontium was now the most important Roman military position N of the Cheviots. The barracks were of wattle-and-daub set on stone sill-walls, and their size suggests that they were designed for legionaries. About A.D. 100 this phase terminated in disaster, and an interval of some 40 years elapsed before the third fort was built during the Antonine reoccupation of the Lowlands. Enclosing an area of 5.9 ha, the early Antonine rampart was faced with a stone wall, in front of which there were two ditches.
The buildings of this period are known in some detail. The praetentura contained 12 barracks, while the main buildings comprised a principia; two horrea, one on either side of the principia; and a praetorium with private bathing establishment. The retentura was cut off from the rest of the fort by a dividing wall with a single central gateway flanked by towers: this feature, unique in Britain, is best explained by the fact that the garrison was a dual one, a legionary vexillation occupying the praetentura, while the retentura housed a regiment of auxiliary cavalry. The fourth fort, of late Antonine date, succeeded the third after a brief interruption. Although the existing curtain wall was retained, the rampart backing was increased in width and a third ditch added. Inside the fort the dividing wall was demolished and new barracks and stables erected for an ala milliaria. The date of the final abandonment of the site is uncertain, but occupation may have extended into the 3d c.
Outside the fort were annexes of different periods on all sides except the N; the W annex contained a courtyard building, perhaps a mansio, and a bath house. A number of temporary camps and a small roadside post of Flavian date have also been found in the area while a signal station, of which traces are still visible, has been identified at the N end of the Eildons. The excavations of 1905-10 produced rich finds, now in the National Museum of Antiquities of Scotland. Most of these came from pits in the S annex. Especially noteworthy are the arms and armor of both legionaries and auxiliary troops, tools and other items of daily use, and large quantities of pottery.
BIBLIOGRAPHYJ. Curle, A Roman Frontier Post and its People (1911); Proc. Soc. Ant. Scotland 84 (1950) 1-38; 86 (1952) 202-5; Inventory of the Ancient & Historical Monuments of Roxburghshire 2 (1956) 312-20; Britannia 3 (1972) 53-54.
K. A. STEER