The search for the origins of the process of denization in England has traditionally focused on the needs of merchants and the context of international trade, and no credible explanation has been given for why denization emerged as a recognisable Chancery form in the 1380s and 1390s. A new consideration of wartime treatment of aliens demonstrates the slow emergence, between c.1250 and c.1400, of an official policy towards lay foreigners that sought to minimise the disruptions arising in moments of national emergency and to accord rights of denizen equivalence to foreigners whose presence was profitable to the realm. In certain exceptional conditions during the 1270s and 1340s, alien residents with good connections at court could secure more developed statements of their rights as denizens. However, it was a series of events set off by the announcement of an intention to expel all French residents in 1377–78 that generated letters of protection containing specific reference to a change of allegiance, and thus established the principle that the recipient should renounce his former commitment and became a subject of the English Crown. Applied to other nationalities and outside the immediate context of war, these developments would give rise to the form known as letters of denization during the decades that followed.
- Middle Ages