Who were the Habsburgs, Maria Theresa, Franz Joseph and Sisi? And how did they shape Vienna? What is the Ringstrasse, and why are there so many oversized, ornate public buildings dotting it? Where did Mozart perform as a 6-year-old prodigy? When and why did Austria shrink to a tenth of its size? What do the eagles on the rooftop of St. Stephen’s Cathedral symbolize? And why are Vienna’s coffee and pastries so legendary?