The Archean Eon represents 1.3 Gyr of Earth's distant past, from about 3.8 Ga to 2.5 Ga-nearly one third of our planet's history. It was during the Archean that a regime of global geodynamics was established, resulting in the formation and recycling of the first lithosphere, as well as the formation, growth, deformation, differentiation, emergence, and erosion of continents. By the end of the Archean, Earth had reached a geodynamic regime dominated by plate tectonic processes. The consequent environments, at and near Earth's surface, included the different niches within which early life forms evolved. It is to the Archean evolution of Earth that we now look to better understand many of the processes that shaped the planet, as we know it.