Cosmology, as we understand it today, is a very young science, mostly due to the fact that making observations is hard. Despite that, however, speculations regarding the nature of the universe can be found in many ancient sources, such as the written works of ancient Greek philosophers. The beginning of cosmology as a science rather than a topic in philosophy is closely related to the invention of telescopes. However, it took a few hundred years until a proper theoretical foundation was set for cosmology with the development of thermodynamics and later general relativity and quantum mechanics. All of this and more will be discussed in this talk on the history of cosmology by Prof Malcolm Longair, the Emeritus Jacksonian Professor of Natural Philosophy at Cambridge University, who happens to be a very enthusiastic lecturer.