The diverse evidence, combined, indicates that northeastern Africa is the centre of origin of the dessert watermelon, that watermelons were domesticated for water and food there over 4000 years ago, and that sweet dessert watermelons emerged in Mediterranean lands by approximately 2000 years ago. Next-generation ancient-DNA sequencing and state-of-the-art genomic analysis offer opportunities to rigorously assess the relationships among ancient and living wild and primitive watermelons from northeastern Africa, modern sweet dessert watermelons and other Citrullus taxa.