Chalcedon
The site of Chalcedon is located on a small peninsula on the north coast of the Sea of Marmara, near the mouth of the Bosphorus. A stream, called the Chalcis or Chalcedon in antiquity and now known as the Kurbağalıdere (Turkish: "stream with frogs"), flows into Fenerbahçe bay. There Greek colonists from Megara in Attica founded the settlement of Chalcedon in 685 BC, some seventeen years before Byzantium.
Chaldean Catholic Church
The Chaldean Catholic Church (, "ʿīdtha kaldetha qāthuliqetha"; Arabic: الكنيسة الكلدانية "al-Kanīsa al-kaldāniyya"; ) is an Eastern Catholic particular church ("sui juris") in full communion with the Holy See and the rest of the Catholic Church, with the Chaldean Patriarchate having been originally formed out of the Church of the East in 1552. Employing the East Syriac Rite in Syriac language in its liturgy, it is part of Syriac Christianity by heritage. Headquartered in the Cathedral of Mary Mother of Sorrows, Baghdad, Iraq, since 1950, it is headed by the Catholicos-Patriarch Louis Raphaël I Sako. It comprises 640,828 members, mostly Chaldean Christians living in northern Iraq, with smaller numbers in adjacent areas in northeastern Syria, southeastern Turkey and northwestern Iran, a region roughly corresponding to ancient Assyria. There are also many Chaldeans in diaspora in the Western world.