The oldest reference to Graz in historical documents is from 1128. In 1379 Graz became the capital of Inner Austria. ("Inner Austria" included Styria, Carinthia, Krain, Inner Istria and Trieste.) The Roman Empire used Graz as a stronghold to defend against enemies on the southeast. Two of the buildings created at that period ("Glockenturm" which is a clock tower, and "Uhrturm" which is a bell tower) have become landmarks of Graz.