Magnetic Monopoles -- From Dirac to the Large Hadron Collider

One of the basic properties of magnetism is that a magnet has always two poles, north and south, which cannot be separated into isolated poles, the magnetic monopoles. There are strong theoretical arguments in favour of monopoles’ existence, but in spite of extensive searches they are yet to be found. In this review article, after highlighting briefly the theoretical foundations of monopoles, a historical overview of experimental endeavours to observe them is given, with emphasis on the state-of-the-art of searches in cosmic and collider experiments and in particular the Large Hadron Collider at CERN.