The main street leading to the palace is the Byzantine processional Mese Avenue, today Divan Yolu (Street of the Council). The Mese was used for imperial processions during the Byzantine and Ottoman era. It leads directly to the Hagia Sophia and takes a turn northwest towards the palace square where the landmark Fountain of Ahmed III stands. The sultan would enter the palace through the Imperial Gate (Turkish: Bâb-ı Hümâyûn or Latin: Porta Augusta), also known as “Gate of the Sultan” (Turkish: Saltanat Kapısı) located to the south of the palace. This massive gate, originally dating from 1478, is now covered in 19th Century marble. The massiveness of this stone gate accentuates its defensive character. Its central arch leads to a high-domed passage. Gilded Ottoman calligraphy adorns the structure at the top, with verses from the Qur’an and tughras of the sultans. Identified tughras are of Sultan Mehmed II and Abdül Aziz I, who renovated the gate.
One of the inscriptions at the gate proclaims:
By the Grace of God, and by His approval, the foundations of this auspicious castle were laid, and its parts were solidly joined together to strengthen peace and tranquility. May God make eternal his empire, and exalt his residence above the most lucid stars of the firmament.
On each side of the hall are rooms for the guard. The gate was open from morning prayer until the last evening prayer.
According to old documents, there was a wooden apartment above the gate area until the second half of the 19th Century. It was used first as a pavilion by Mehmed, later as a depository for the properties of those who died inside the palace without heirs and eventually as the receiving department of the treasury. It was also used as a vantage point for the ladies of the harem on special occasions.
The Imperial Gate is the main entrance into the First Courtyard. The four courtyards lead to each other and during the Ottoman Empire, each became steadily more exclusive leading to the Fourth Courtyard, which was the sultan’s private courtyard.