The Brassica oleracea species, encompassing cabbage, Brussels sprouts, and kale, represent a diverse and economically important group of cole crops within the Brassicaceae family. Originating from a common ancestor in the Mediterranean region, these crops have been cultivated since ancient times, exhibiting significant variability across their varieties and types. This chapter provides a comprehensive overview of genetic resources associated with these cole crops, focusing on their botany, origin, domestication, and geographical distribution. It explores the primary gene pool, wild genetic resources, and strategies for their collection and conservation, highlighting existing gaps and challenges in both geographical and genetic diversity. Additionally, it identifies gaps in genetic diversity and suggests thrust areas for future germplasm collection and characterization. By evaluating the breeding options and the incorporation of desirable traits, this chapter aims to provide insights into the future perspectives of these essential crops, underscoring their significance in global agriculture and food security.