The procurement of grain has been a major preoccupation for the Maltese inhabitants surely since the later years of the Middle Ages. In 1398, when the population is believed to not have exceeded the figure of 20,000 inhabitants, Malta managed to obtain tax concessions from Sicily on its transfer. The grain silos are containers where these huge amounts of grain that were imported were then stored. The Fort St Elmo silos, also referred to as fossae, were excavated during the reign of Grand Master de Redin in the middle of the 17th century.

If the silo was left airtight and watertight, the grain within managed to remain in good condition for several years. An interesting account tells the story of an individual who passed away because of the foul air in the silo following its opening. Another recalls the sight of insects and pests crawling out of them. Notwithstanding, the silos proved providential in cases of sieges or else in periods in which grain was not managed to be procured from neighboring lands. The Fort St Elmo grain silos once numbered to a figure of 70. However, at present only 39 remain because they had to make way for the nearby roads and buildings.