
TheProsphorion Harbour (Greek:Προσφόριον) was a harbour in the city ofConstantinople, active from the time when the city was still the Greek colony ofByzantium (657 BC – 324 AD), until the eve of the first millennium.[1][2] Gradually enlarged, it was the first port to be built in the area of the future Constantinople.[1][2]
The harbour lay on the southern shore of theGolden Horn, east of today'sGalata Bridge, in the fifth region of Constantinople, where thesea walls made a deep nick, in correspondence of theByzantine Gate of Eugenius (the OttomanYalıköşkü kapısı),[2] and extended successively westwards, finally occupying the first inlet after theestuary entrance. The inlet where the basin once lay is now silted up, and corresponds today to the east part of theSirkeci railway station area, south of theOttomanSepetçiler köşkü.[2] Administratively, the site belongs to theMahalle ofHoca Paşa inEminönü, which is part of theFatih district (thewalled city) ofIstanbul.

The first harbour to be built in Constantinople's area during the time when it was the city-state ofByzantium lay on theGolden Horn, at the entrance of theBosporus, in the angle formed by the sea and the end of Byzantium's walls, corresponding with the future Byzantine quarter named "ta Eugeniou" (Greek:τὰ Εὑγενίου) after the Gate of Eugenius of the sea wall (the OttomanYaliköşkü kapısı).[1] Its position lay immediately under the northwest slope of thefirst hill of the city.[1] Thanks to its location along the southern shore of the Golden Horn, the harbour was protected from the heavy storms provoked by theLodos, the south-west wind blowing from theMarmara Sea.[1] After the reconstruction of Byzantium following its destruction underSeptimius Severus (r. 193–211), the harbour grew to the west, finally enclosing the whole area today occupied by the Sirkeci railway station and its dependencies.[1] The first landing place to be met at the east, possibly lying near the Gate of Eugenius, was named afterTimasius (d. 396), a high officer active underEmperorsValens (r. 364–378) andTheodosius I (r. 379–395).[1] Right after the foundation of Constantinople byConstantine the Great in 324, the port received the name of "closed harbour" (Greek:κλειστός λιμήν,kleistos limen) since it was protected by moles and defended by the sea walls and by the Tower of Eugenius.[2]
The name of "Prosphorion", which the harbour assumed after the foundation of Constantinople, could derive either from its proximity to the city market (Greek:πρόσφορον),[1] or from another denomination of the place,Phosphorion (Greek:Φωσφόριον), because of a legend which sawHecatePhosphoros ("Light-Bringer") helping there during the night the defenders of Byzantium besieged byPhilip of Macedonia.[3] Another theory assumes that the name came from the nearby market of the oxen (Greek:βοσπόριον, βοόσπορος, βόσπορος), which lay nearby, until it was moved by EmperorConstantine V (r. 741–75) to near theForum Tauri.[1]
About two hundred years before that,Justinian I (r. 527–65) had already moved the market of the sea goods from the Prosphorion to the largerPortus Sophiae on the Marmara Sea.[1] Inside the harbour, a landing place, theScala Chalcedonensis, had been reserved for the inhabitants ofChalcedon, on the opposite side of the Bosporus.[1] Despite that, the port had a purely commercial function: at the Prosphorion landed the commodities imported from the Bosporus, theBlack Sea and Asia.[1] As a result, the area was surrounded by many storehouses: theNotitia Urbis Constantinopolitanae records that during the 5th century four out of sixhorrea present in the city lay in the Prosphorion area.[2] However, the harbour was subjected to heavy silting, so that at the eve of the first millennium it was definitively blocked by the mud.[2] Its only surviving function until the latePalaiologan period was that of dockyard (Greek:ναύσταθμος,naustathmos) for theEmperor during his trips from thePalace of Blachernae to theHagia Sophia cathedral.[2] The dockyard lay just in front of the Gate of Eugenius, known in that period as the "Royal Gate" (Greek:πυλή βασιλική,pyle basilike), since the Emperor had to cross it in order to reach the church.[2]
In 1457, shortly after thefall of the city in 1453 to theOttoman Empire, the neglected harbour was included in the area protected by the walls of the newly builtSultan's palace.[2]