The Iron Pnictide Superconductors : An Introduction and Overview Introduction Fe based superconductors: Materials phase diagrams and spectroscopy Modeling many body physics in Fe superconductors and other multi orbital materials with the Slave Spin mean field: Mott and Hunds physics Cooper pairing magnetic frustration and spin fluctuations in iron based superconductors. Nematic order and fluctuations in iron based superconductors. This book covers different aspects of the physics of iron based superconductors ranging from the theoretical the numerical and computational to the experimental ones. It starts from the basic theory modeling many body physics in Fe superconductors and other multi orbital materials and drreaches up to the magnetic and Cooper pair fluctuations and nematic order. Finally it offers a comprehensive overview of the most recent advancements in the experimental investigations of iron based superconductors. .