Blachernae was a suburb in the northwestern section of Constantinople. It was the site of a spring and a number of churches were built there, notably by Pulcheria in the 5th century and by Justinian I in the 6th century. These were originally outside the city walls, until 627 when the walls were expanded to include this section of the city. The area was expanded to include an imperial palace in the 11th century by Alexius I, but the walls were still relatively weak, reinforced only by the rampa… (More on Blachernae)