Sireviruses is an ancient, and with a unique genome structure, LTR retrotransposon genus of the Copia superfamily, and the only one that has exclusively proliferated within plant genomes. However, as a result of receiving little research interest until now, the extent of their colonization and impact on their host genomes remained unclear. Here, aided by the recent development of a purpose-built algorithm, we report that Sireviruses have infiltrated most phylogenetic branches of the plant kingdom, extensively colonizing genomes such as that of soybean, sorghum and lotus, whilst reaching massive numbers in maize to form a plethora of autonomous and non-autonomous families with distinct genome characteristics, some outlined herein for the first time. In maize, Sireviruses occupy 21% of the genome and comprise 90% of the Copia population, experiencing intense amplification during the past 600,000 years, and mediating the formation of gene islands by targeting their own genomes in chromosome-distal gene-rich areas. Intriguingly, this spatial and temporal integration pattern is not universal, as evident by their pericentromeric preference in soybean and by their much older amplification burst in cacao. To support further studies into these infiltration patterns, their evolutionary depth and impact on their hosts, and also facilitate the numerous genome annotation projects, we developed a database that catalogues and analyzes the complete Sirevirus populations of eleven fully-sequenced plants, currently housing approximately 16,200 elements. Overall, this multi-faceted work brings for the first time Sireviruses, together with a unique set of tools and data for the scientific community, under the spotlight (http://bat.infspire.org/sireviruses/).