Longevity is defined as the extent to which seeds can remain alive during storage. It is an essential seed trait that serves to bridge the time between seed abscission until germination, and underpins global agriculture and plant species conservation. Over the past decade, the research field in longevity of orthodox seeds has seen major developments. Focussing mostly on data of controlled storage conditions in the laboratory, this chapter highlights the main discoveries in these areas. The areas that will be discussed are related to the extent of seed life spans in Angiosperms, the advances that have been made using natural or induced genetic diversity, and how the genetic programs governing seed longevity are strongly dependent on the growth conditions during seed development in a genotype-dependent manner, reflecting plasticity and adaptation. A final section focusses on the use of various ageing protocols and the limits of extrapolating accelerated ageing conditions.