Perhaps the earliest reference to human habitation…

Perhaps the earliest reference to human habitation in the area now known as Dublin is provided in the writings of the Greek astronomer and cartographer Ptolemy, who had referred in around 140 to a settlement he called Eblana Civitas.

The settlement 'Dubh Linn' dates perhaps as far back as the first century BCE and later a monastery had been built there, though the town itself had been established in about 841 by the Vikings.

It is now thought that the Viking settlement was preceded by a Christian ecclesiastical settlement known as Duiblinn, from which Dyflin took its name.

Beginning in the ninth and tenth century, there were two settlements where the modern city stands.

The Viking settlement of about 841 is known as Dyflin, from the Irish Duiblinn (or "Black Pool", referring to a dark tidal pool where the River Poddle enters the Liffey on the site of the Castle Gardens at the rear of Dublin Castle); a Gaelic settlement, Áth Cliath ("ford of hurdles") is further up river.

The Celtic settlement's name is still used as the Irish name of the modern city, though the first written evidence of it is found in the Annals of Ulster of 1368.

The modern English name comes from the Viking settlement of Dyflin.

The Vikings, or Ostmen as they call themselves, are to rule Dublin for almost three centuries, though they had been expelled in 902 only to return in 917.

Viking settlers in 992 establish a mint in Dublin to produce silver pennies.