Compared to insects, fossil spiders have received only scant attention in the literature. Previously, the only works available were numerous scientific papers, many published in foreign languages. Most of these are basic descriptive taxonomic works, with very few considering broader biological concepts. Despite a significant increase in the discovery and description of fossil spiders within the last quarter Century this void remained unfilled. Thus, this short monograph aims to achieve several objectives. Firstly, to provide general and up to date background information on the overall importance and diversity of fossils spiders, including an indication of those groups for which the taxonomy is spurious and in need of reassessment. Secondly, to discuss the techniques available for working with fossil spiders and some of the problems encountered by palaeoarachnologists, including bias and limitations of the spider fossil record. Thirdly, the overall evolutionary history of spiders is summarized in the form of an evolutionary tree, which is subsequently used to address key issues of broad interest, such as origins, diversifications and extinctions, including the effects of mass extinctions and predator-prey co-radiations. Finally, the contribution that fossil data can make to understanding the past and present biogeography of the order is considered. This book should be of interest to both amateur and professional arachnologists and palaeontologists and will also serve as a general palaeontological reference work for neonologists studying extant spiders.