Name:Accordingtomostofthecontemporaryresearchers, thenameTrimammiumisofLatinoriginandmeansthree-breast site. It reflects the local topography – three close hills on the Danube riverbank, on one of which is located the Roman fort.

Written sources: Trimammium is mentioned for the first time in the Roman road map - itinerarium, composed by Claudius Ptolemy around the middle of the 2nd century, as Trimammion (Τριμάμμιον; Τριμμάνιον). WiththenameTrimamioandTriamo (Trimamio, Trimammio, Triamo) it is presented in other road maps – Tabula Peutingeriana and Itinerarium Antonini, which refect the geographical reality in the time of emperors Augustus and Caracalla. There, along with the name of the fort, are indicated the distances in Roman miles to the neighboring forts of Yatrus/Scaidava and Sexaginta Prista. Inthe “ListofOffices” (Notitia Dignitatum), written in the end of the 4th-the early 5th century, are mentioned military units (milites Constantini), stationed in Trimammio (Trimammio). ForthelasttimeTrimammiumismentionedintheAnonymousRavennaCosmographyasTrimamion (Trimamion).

Location: Trimammium is located on the Danube riverbank, in the area of the Stalpishte locality, which stands around 3 km to the northwest from the village of Mechka, Rousse region, and 22 km to the southwest from Rousse. The local population calls it “Kaleto” and its area is around 24 decares.

Historyoftheresearch:Thefortislocalizedonthebaseoffieldobservationworkby Karel Skorpil and Mihail Vankov in 1905. They also described the belonging unfortified settlement and necropolis.Particularly interesting are the evidences for a rock relief of the Thracian horseman and a rock-hewn church at the dry-land of the Oreshe river. The monument has been destroyed by treasure-hunters in 1940. In 1983 trenching excavations are conducted in search for the necropolis in the Dervisha area, but no graves were found.In the period 2006-2009, following treasure-hunter interventions, rescue archaeological excavations were undertaken in the southern section of the fort. Around 270 m2 were excavated.  

Revealed structures:In 2006-2009 was examined Trench A, with area of 225 m2.  Therewererevealedtheremainsofatleastfivebuildings, ofwhichonlyoneisentirelyexamined, fourotherwalls, twolime-pits, 21 pitsofdifferentperiodsandastonekiln.

In 2009 TrenchBwasconducted, withareaof 45 m2. Here were revealed sections of three overlapping, different in chronology fortification walls. Two buildings and two pits from the Late Antiquity are attached to them. In proximity to the remains of the fortification walls is positioned a small Medieval church.  

Finds and chronology:

At this stage, no structures prior to the 2nd century AD are revealed within the studied area. There are such to the east of it, on a neighboring hill. Here are registered dug-outs with pottery from the Early Iron and the Late Iron Ages. During excavation works in 1978 was unearthed a coin hoard, dated in the 2nd-1st century BC.

A total of 468 coins are discovered during the excavations, with 187 of them being from the 2nd-3rd century period, 258 are from the 4th-5th century, nine are from the 6th century, three are from the 11th century and eleven – from the 13th century.

Theearlieststructuresaretheremainsofabuilding (BuildingE), overlappedbythebuildingwithhypocaust (BuildingB). Within its context is discovered a denarius of Emperor Trajan and over 350 iron arrowheads. Until now there are no finds prior the 1st century, except for one heavily worn-out republican denarius. The coins and other finds, dated in the 2nd century, are several, but are discovered within later contexts.

In the beginning of the 3rd century was constructed Building B, of which only the southwestern short side has been studied. Three premises of it have been unearthed, one of which has been heated with hypocaust. It was filled at the very end of the 3rd century, the evidence for which is a small hoard of antoniniani, discovered inside the filling.The building has been transformed and used again in the 4th century.

Seven of the discovered pits are dated in the 3rd century. Two of them are from the very beginning of the century (there are found coins of Septimius Severus), and the others are from the end of the century. Large quantity of coins and other finds are found inside two of the pits, which allow their interpretation as ritual ones.Insideoneofthemarefound 39 antoniniani (fromemperorsGallienustoDiocletian), abronzestatuetteofVenus, bronzeumboofashield, ironhelmetcheek-pad, bronzebeltbuckle, medicalinstrument, ironnails, fragmentsofglassandpotteryvessels, aswellasoftiles. Insidetheotheronearefound 11 antoniniani (fromemperorsGallienustoProbus), togetherwithfragmentsofglass, iron, stoneandceramicitems, amongwhichareatilewithstampCORTISIBRAand 15 fragmented loom weights. Inside the pit, over fish bones, is placed a bowl with its bottom upwards.

The dating of Building C is also placed in the period prior the 4th century, with one of the walls used during the construction of the entirely excavated Building A.The latter is built in the beginning of the 4th century and functions at least until the beginning of the 5th century. It is cleared that during the second half of the 5th century the building is not functioning – a large pit is dug inside it.It is repaired in the 6th century and used until the abandoning of the fort in the end of the century. From the discovered 258 Late Roman coins there are none from the second half of the 5th century. From the 6th century there are nine coins, the latest of which is from emperor Mauricius.

Seven of the studied pits refer to the period 4th-6th century. One of them is dated well in the first half of the 4th century according to the coins, discovered inside, as well as by other finds. It is probably related to Building A. Inside another of the pits, which is dated in the 5th century, there are a millstone, fragments of clay lamps, bone comb, coins and other finds. It is dug into the outlines of Building B.

A very small section of the fortification wall of Trimammium is studied, and for this reason its chronology is not entirely cleared. It is certain that in the 3rd century (and probably in the 2nd century) it has already been constructed. To this period is also referred the unearthed small section of regular blocks, with preserved height of around 2 m. Here is also cleared a small section of a postern or an entrance. Traces of repair works are found at the very end of the 6th century.

Follows a period when the fortress was not permanently inhabited. There are stable traces for such presence in structures from the 10th-11th century. Along with the revealed three coins and other typical finds, to the period refer the remains of a dwelling and several pits. The last in chronology remains of a fortification wall are also referred to this period.

The last remains are from the period of the Second Bulgarian Kingdom – as structures, these are a dwelling and a small single-nave church. To the period refer 11 imitation scyphates. Probably the end of the settlement was put during some of the 13th-century Tatar invasions.