Megaron (Nov 2020)
A Byzantine Structure from the Thracian Hinterland of Istanbul: Haramidere Cistern
Abstract
No monograph has been published on the ruins of a 22x10 meters-size Byzantine structure, located along the current E5 Highway in the vicinity of Haramidere region on the route of ancient 'Via Egnatia'. In some scientific reports, it was suggested that the building could be ruins of a Byzantine palace called Aretas as understood from literary sources, while in some others it was argued that the building was an Ottoman menzil, a caravanserai, on the old trade route. However, a re-examination of the available evidence allows for some tentative remarks to be made on the original function of this structure. These constitute the main subject of this article, including the discussion on the necessity of defining the building as a water reservoir. From the fifth and sixth centuries onwards, it is observed that many cisterns usually consisting of two or four rows of columns were built in İstanbul. These structures show similar characteristics in the terms of their construction techniques, commonly representing square or rectangular ground plans. The interiors of the cisterns were divided into naves and the vaulting of the cisterns were supported by rows of columns or in few examples by piers. In these cisterns, a traditional system was used consisting of monolithic columns with arches connecting them with each other and with the walls. The columns were usually topped by spolia capitals showing varying degrees of physical damage. Brick arches bridged the gap between columns and each of the square bays thus formed were canopied by brick vaults or in some examples by domes. It is noteworthy that the vaults were usually built without any wooden framework. Some vaults have openings to draw water from the cistern. The walls are plastered at the height of the spring of vaults by thick layer of waterproof hydraulic mortar, an indicator of maximum storage level. In some examples remnants of a staircase were attached to the wall as an original feature. To increase resistance to the water pressure, the corners between adjacent walls typically contain chamfered or curved reinforcement. Spring water was conveyed by the vaulted aqueduct channels that utilized different elevations to ensure distribution through the city. There were reservoirs and water distribution chambers (castella divisorum) to distribute the water across the city through inverted siphons to cross valleys. The water was delivered to public or private buildings through marble, terracotta or lead pipes. Limited information can be found in the literary sources regarding water distribution and supply for several public and private buildings. In contrast, surviving remains of barrel-vaulted channels and pipelines sometimes appear during the rescue excavations for construction activities. Some archaeological evidence confirms that the water channels were distributing the water within the city from main conduits. Especially during the middle and late Byzantine periods, along with the decline of the water supply system of the city, it seems that numerous cisterns were built in the monasteries and also various substructures were transformed into cisterns. In this respect, cisterns found in almost all of the churches in the Historical Peninsula of İstanbul were either originally built as such or were otherwise converted from underground chambers. Returning to the structural remain at Haramidere, the construction techniques including alternating courses of brick and stone, buttressed interior walls and angled corners, presence of the thick layer of hydraulic plaster on the interior walls, and vaulted water-supply channels unearthed around the site indicate that this partial subterranean structure was a covered cistern that once provided water to the related buildings of a complex or to a site nearby. Although the vaulting of the building has not survived, evidence suggests that the vaulting of the cistern was supported by single row of five columns. Only one fragment of a marble column remained from the cistern was discovered on site during previous excavations. The architectural features of the structure share similarities with the typical late Byzantine period buildings in the capital of Eastern Roman Empire. This paper aims to discuss various hypotheses regarding the identity of the building and to document the architectural features that demonstrate its original function.
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