This chapter explores the precursors to clinical electroencephalography (EEG), tracing its development from early studies in electricity to the foundational discoveries of brain electrical activity. Beginning with William Gilbert’s coining of the term “electricity” in 1600, the narrative follows advancements in static and frictional electricity, the invention of the Leyden jar, and the voltaic pile, culminating in the concept of animal electricity introduced by Luigi Galvani. Emil du Bois-Reymond further advanced the field by linking electrical activity to nerve and muscle function, while Hermann von Helmholtz measured nerve impulse speed, laying the groundwork for neurophysiology. Pioneering studies of brain activity began with Richard Caton’s 1875 demonstration of electrical currents in animal brains, followed by Adolf Beck’s 1887 experiments documenting brain rhythms and evoked potentials. Willem Einthoven’s invention of the string galvanometer in 1901 significantly improved the precision of current measurement, a milestone leveraged by Vladimir Pravdich-Neminsky in 1913 to record spontaneous brain waves in dogs, introducing the term “Elektrocerebrogramm.” However, it was not until Hans Berger’s seminal work in the early twentieth century that EEG emerged as a recognized tool in neuroscientific research and medicine. This chapter highlights the interdisciplinary advances and the perseverance of pioneering researchers that enabled the discovery and application of EEG technology as a way to better understand brain function.