This Demonstration showcases Wolfram Language capabilities in identifying authorship from real-life letters written by three very famous historical personalities who lived during the same period in 18th century Austria and also knew each other quite well. These are Empress Maria Theresa, her son and co-regent Emperor Joseph II and the genial musician Wolfgang Amadeus Mozart. Machine learning is applied to the original German texts reported in the Initialization section. In the Manipulate panel you can switch between reading the English translation and the original German texts used as training samples and snippets. By clicking on the button "English translation with notes" you can also learn some more details about the text content and its authorship. In the training samples only the effective real authorship is reported, as these texts are chosen to train the machine learning (ML) classifier. For snippet texts, both the real and ML predictions are reported.