Astronomers have successfully observed a great deal of the Universe's history, from recording the afterglow of the Big Bang to imaging thousands of galaxies, and even to visualising an actual black hole. There's a lot for astronomers to be smug about. But when it comes to understanding how the Universe began and grew up we are literally in the dark ages. In effect, we are missing the first one billion years from the timeline of the Universe. This brief but far-reaching period in the Universe's history, known to astrophysicists as the 'Epoch of Reionisation', represents the start of the cosmos as we experience it today. The time when the very first stars burst into life, when darkness gave way to light. Incorporating the very latest research into this branch of astrophysics, this book sheds light on this time of darkness.