I want to know the answer to the following question:
In what year was Upper Alsace sold to the Archduke Sigismund?
All the background I'm provided with is that "In 1469, following the Treaty of St. Omer, Upper Alsace was sold by Archduke Sigismund of Austria to Charles the Bold, Duke of Burgundy.". Is that enough to answer the question?
Answer: yes