The silver coin you've described is a common coin type from the medieval period, specifically minted during the reign of Edward I (1272-1307). Edward I is renowned for his initiatives, such as building castles in Wales and relocating the Stone of Destiny from Scotland to London.
However, the significance of this particular coin lies in its connection to the Isle of Man, where it is just one among more than 300 coins discovered at Ballasligh, near Douglas. In an era before the existence of banks, people often concealed their savings in the ground during times of hardship. Occasionally, these individuals were unable to return to retrieve their buried wealth, and these stashes remained hidden until recent discoveries were made. The field where this particular hoard was found is now known as Silver Field, commemorating this remarkable find.
The late 1200s marked a turbulent period on the Isle of Man, with the Anglo-Scottish wars unfolding across Britain. Given the prevailing circumstances, it is unsurprising that this hoard was buried as a prudent measure for safekeeping, reflecting the uncertainties and challenges of the time.