On Dublin

The name Dublin is an Anglicism of Dubh Linn (Irish, meaning "Black Pool"), though some doubt this derivation. Historically, in the old script used for the Irish language, 'bh' was written with a dot placed over the 'b'—thus appearing to be Dub Linn or Dublinn. The Norman-speaking English who arrived in Old Irish-speaking Ireland starting in 1169 had no idea the dot over the 'b' signified it was really 'bh,' so they omitted it and spelled the town's name as 'Dublin'.

Meanwhile, the city's name in Modern Irish—Baile Átha Cliath ("The Town of the Ford of the Reed Hurdles")—actually refers to the settlement, founded in 988 by High King Mael Sechnaill II, which adjoined the town of Dubh Linn proper, at the Black Pool.

Some have suggested that "Dublin" is of Scandinavian origin, cf. Icelandic: "djúp lind" ("deep pond"). That does not work for two reasons. First, the name "Dubh Linn" pre-dates the arrival of the Vikings in Ireland. Second, the Old Norse name for Dublin is simply the words "Dubh Linn" re-spelled as if they were Old Norse: Dyflin (correctly pronounced "DUEV-linn" - indeed, the letter 'y' is still pronounced like the vowel in "ewe" in Modern Norwegian, Swedish, etc., just as it was in Old Norse).