Computational History of Science' addresses questions of history by evaluating historical data, e.g. for tracing back copying traditions and conclude on transfer and transformation of data and knowledge. Modern computational history, of course, relies on the technologies of the digital humanities. The term `Applied Historical Astronomy', in contrast, tries to address questions of contemporary science by evaluating historical data in comparison with most recent data. This term was introduced in the 20th century, but the method behind the term is much older. Here we give an introduction to the topic that is based on a review by Steele (2004) and enriched by our observations in the subsequent years. This way, we explain why and how the topic is still interesting. Basically the introduction of new methods of computational science developed in the recent years opens new possibilities. This introduction presents successes and open questions in the search for stellar transients among historical data.