the Baby Einstein, Newton, the Solvay conferences, some classical thought experiments, principles, and effects we associate with the general theory of relativity, as well some newest results such as the holographic principle at the end. Robbert's presentation is poetic so some wise quotes by Einstein are included.If we ignore the "partially" independent efforts by David Hilbert etc., general relativity was a result of a pure scientific enterprise by a solitary genius. When he discovered special relativity (and other things) during his miraculous year of 1905, Einstein wasn't satisfied. Newton's laws of gravity were incompatible with special relativity (for example because Newton's gravity was thought to act immediately i.e. faster than light – but more mathematically because such an instantaneous action simply violates the Lorentz symmetry) and after aPoincaré transformations – the "special" changes of the observer – which is why the original relativity was renamed to "special relativity". Similarly, one needs the more general, nonlinear coordinate transformations and the equivalence of all observers, including the accelerating ones, which is why the "new" relativity became known as the "general theory of relativity".Once the equivalence principle became a core of Einstein's thinking, the path towards the final equations was wide open. Einstein had to learn the Riemannian geometry – which has been available in the mathematics books since the 19th century – and go through almost all the possible technical mistakes you can think of. For example, before he found the final form of the equation, he had equations where the Einstein tensor was replaced by the