Operation Overlord, launched 80 years ago on June 6, was a critical Allied mission to recapture Europe from Nazi control.

Central to its success were two relatively unknown figures from north Wales: Jack Darbyshire and Hugh Iorys Hughes.

Jack Darbyshire, a brilliant mathematician from Blaenau Ffestiniog, attended Bangor University and later worked at the Admiralty Research Laboratory in Teddington.

There, he excelled in predicting wave conditions, crucial for planning the sea invasion.

His team developed early computer models to predict wave patterns, aiding in the selection of the invasion date.

Concurrently, Hugh Iorys Hughes, an engineer from Bangor, designed the Mulberry Harbours—mobile harbours essential for the invasion's logistics.

Testing his prototypes in Conwy Morfa with a team of over 1,000 people, Hughes' harbours were eventually used at Omaha and Gold beaches, proving vital for the delivery of supplies and reinforcements.

Their contributions, though often overlooked, were instrumental in the success of D-Day.