Any consideration of the history of zero must first discuss the origin of numbers, specifically the counting integers. Central to the focus of this book, zero doesn’t appear as an actual number in any ancient numbering system! The emergence of zero as a number in itself, and not in its role as a position marker, may have been delayed due to its cognitive association with the void, which had such strong negative connotations that a number representing nothing was unthinkable. Philosophers concerned with such an issue were often the same ancient scholars, who were also astronomers and mathematicians, who would have benefitted from its use in computations. This delay is unfortunate since zero’s final emergence only centuries ago enabled mathematics to blossom and flourish. There is extensive literature on the intricacies of ancient mathematics, as many of their constructs still underpin modern practices, especially in algebra and geometry. This chapter’s goal is to overview the growth of ancient number systems, introduce the concept of zero in counting and its use in positional numbering systems, and discuss the emergence and ultimate dominance of the zero-containing Hindu-Arabic numerals that globally spread to become the basis of our modern numbering system.