The so-called Palace of the Porphyrogenitus (Turkish Tekfur Sarayı) was located in the region of Blachernai (modern Ayvansaray) in the northwestern corner of Byzantine Constantinople. Its name likely refers to the porphyrogenitus (“purple-born”) Constantine, son of Emperor Michael VIII (1259–1282). It was built on a hill above the Blachernai Palace, as a separate yet closely related complex. It opened as a museum in 2019 following a controversial reconstruction.

The structure seems to have been constructed around 1261-1291 following the Byzantine reconquest of Constantinople. It has also been argued that it has an earlier phase perhaps dating to the reign of Manuel I Komnenos (1143-1180) when he constructed new city walls by the Blachernai Palace. Even if it has an earlier phase, the current structure seems related to Michael VIII’s restoration of the Blachernai Palace following his recapture of Constantinople in 1261. It was probably the “House of the Porphyrogennetos” (οἶκος τοῦ πορφυρογεννήτου) mentioned in the 14th century, which was associated with the third son of Michael VIII (1259–1282), the porphyrogennetos Constantine, who was held there under house arrest after 1293 by his brother Andronikos II Palaiologos (1282-1328). The imperial epithet, porphyrogenitus (πορφυρογέννητος “purple-born”) designated children born after their father had become emperor. Michael VIII perhaps chose Blachernai to be his official residence as it was also the main residence of the Komnenian emperors, whose reputation and fame still loomed large at the time. As a distant relative, Michael VIII was keen on associating himself with the Komnenian dynasty, even adding Komnenos to his patronymic. While it is unclear how the Palace of the Porphyrogenitus and the main Blachernai Palace complex were connected, their proximity is surely significant. The Palace of the Porphyrogenitus, which is located on a hill to the south, is around 500 meters from the palace’s northern terrace wall.

The palace played an important role in several key moments of the 14th century. The “House of Porphyrogenitus” is mentioned when Andronikos III (1328-1341) took control of the government from his grandfather Andronikos II in 1328. Andronikos III briefly resided here to be close to his grandfather, who officially retained his imperial insignia and continued to reside in the Blachernai Palace. It also played a key role at the end of the Civil War of 1341-1347, which started when John VI Kantakouzenos (1347-1354), chief adviser and general for Andronikos III (1328-1341), failed to secure the regency for John V after the emperor’s death. Anna of Savoy, wife of the late emperor, instead became the regent for her son John V, and joined Patriarch John XIV of Constantinople and Alexios Apokaukos in opposing John VI Kantakouzenos. In 1346, Kantakouzenos was crowned emperor in Adrianople and the following year he entered Constantinople by breaching the Golden Gate, which had been walled up. He then marched to the House of the Porphyrogenitus above the Blachernai Palace, where the Empress Anna of Savoy was residing. Kantakouzenos forbad the palace to be attacked, and began negotiations for her to surrender. However when she sent messengers away, some officers of Kantakouzenos became so infuriated that they disobeyed his orders, set fire to one of the gates, and stormed the palace. In the end, Anna was persuaded by her son John V to discuss terms of peace, and once the agreement was signed, the gates of the palace were opened to admit Kantakouzenos as the senior emperor.

John V (1341-1391), who married Helena, the daughter of John Kantakouzenos, was forced remain in the background until a new civil war broke out in 1352. In 1354, John was able to slip into Constantinople at night, after which word spread and the following day mobs began to attack the houses of known supporters of Kantakouzenos. John encamped outside the House of the Porphyrogenitus, just as Kantakouzenos had done a few years before. The mob helped storm the palace, but the emperor's Catalan guards drove them back. John sent a negotiator to the palace, and Kantakouzenos agreed to joint rule, as they had agreed in 1347, though this time Kantakouzenos abdicated a short time later.

The map of Constantinople made by Buondelmonti around 1420 labeled Tekfur Palace as Palatium Imperatoris, suggesting that it might have served as the main imperial residence in the final years of the Palaiologan era. Following the Ottoman conquest, Jewish families from the region of Thessaloniki were settled in the area of the palace. In the 16th century, the palace and a nearby cistern were used to house the sultan’s menagerie. During this time, it began to be called Tekfur Sarayı (“Palace of the Sovereign”) in Turkish, though it was commonly called the Palatium Constantini (“Constantine’s Palace”) by foreign visitors during this period. In the 19th century, it was incorrectly identified as the Hebdomon Palace, and it was commonly called the Palace of Belisarius. One legend claims that the famous “Spoonmaker's Diamond” (Kaşıkçı Elması) was discovered here, though the legend that it was discovered at Yenikapı is more commonly cited; the diamond became part of the treasury of Topkapı Palace during the reign of Mehmed IV (1648-1687).

In the early 18th century, it was decided to bring craftsmen from Iznik, and subsequently a workshop was set up in the courtyard of Tekfur Palace in 1719. The most famous example of the tiles made here can be found in the Fountain of Sultan Ahmed III (1728). Another noteworthy example is a depiction of the Kaaba in Mecca in Hekimoğlu Ali Pasha Mosque (1734). Glass began to be produced at the site in the early 19th century glass. Around the same period, Tekfur Palace was used as a Jewish poorhouse (Yahudihane) until a fire devastated it in 1864. This completely destroyed the interior, leaving it a shell, while other features, such as its main balcony, were severely damaged. Kastoria Synagogue, which served the Jewish community here, was located a short distance east of the palace; the final version, now lost, was in the 19th century and continued to be used until 1937.

There is evidence of repairs to the Tekfur Palace complex made during the Ottoman era, though much more substantial changes were made in more recent years. Restoration work was made between 1955 and 1970, during which time, new marble columns were added and the debris in the palace remains and courtyard was removed. More recently, the building was opened as a museum in 2019, following its controversial reconstruction involving rebuilding the former empty shell of the three story structure and the additions of interior and exterior elevators.