London: four etymologies

But in those days, the Cities of the Brittains were not artificially built with Stone or Timber, but were only thick, and Troublesom Woods plashed together and intrenched round, like to those which the Irish at this day call Fastnesses; Some are of Opinion that whence London had her Fame, from thence she had also a Name, that is, from Ships, which the Brittains call Lough, and Dinan a Town, so that London is no other than Shipton, a Town of Ships; which Title no City hath more Right to assume than this, being scituated upon the gentle Ascent of an Hill, near a gallant Navigable River; which swelling at certain times with the Ocean Tides, she is able by her deep and safe Channel to entertain the greatest Ships, which can bring in all the richest Commodities the World can afford.

Some would have Llwndain the Welsh name of London, to be derived from Llhwn which signifies a fenced Town, made of Trees cast down and barricadoed together, as aforementioned, for so the Poet sings.

— Richard Burton, Historical remarques and observations of the ancient and present state of London and Westminster (1684).

King Luds reedifying Troinovant (first built by Brute) and thence leaving the name of Caer Lud afterward turned (as they say) into London is not unknowne, scarce to any that hath but lookt on Ludgates inner frontispice; and in old rimes thus I have it exprest:

Walls he lete make al aboute and thates up and doun
And after Lud that was is name he clupede it Luds towne.
. . . Thereuore thut after him me clupeth it Ludegate
The toun me clupeth that is wide couth
And now me clupeth it London that is lighter in the mouth.

Judicious reformers of fabulous report I know have more serious derivations of the name: and, seeing conjecture is free, I could imagine, it might be cald at first Lhan Dien .i. the Temple of Diana. . . and so afterward by strangers turned into Londinium, and the like. For, that Diana and her brother Apollo (under name of Belin) were two great Deities among the Britons, what is read next before, Caesars testimony of the Gaules; and that she had her Temple there where Paules is, relation in Camden discloses to you.

— Michael Drayton, Poly-Olbion (1619), illustrations to Song VIII.