'Middle' in the Bible

Then all the officials of the king of Babylon came in and sat in the Middle Gate [establishing both military control of the city and their authority to judge the captives]: Nergal-sar-ezer, Samgar-nebu, Sar-sekim the Rab-saris (chief of the eunuchs), and Nergal-sar-ezer the Rab-mag (chief of the magicians), with all the rest of the officials of the king of Babylon.