"Mercia" means something like "men of the border". Anyone want to speculate on what Murcia/ Marseille/ Masallia might mean?
The tradition explanation for 'Murcia' is that it's named after its supposed founder Medinat Mursiya. As far as I know the English translation for the Arabic 'mursiya' is 'dirge' or 'elegy' (a song or poem of lamentation).
The name for the Greek colony of 'Massilia' is said to come from 'mas' a Ligurian word for 'Spring'. [The adding of the 'r' is supposedly because of the association with the Roman god 'Mars'.] Another point to mention is that the month of March (supposedly named after Mars) is the start of spring and the beginning of the military campaigning season.
As it stands I do not take these explanations as gospel but I do find it interesting that the Arabic 'mursiya' is often performed in concert with a 'marching' procession. We also know that the Carthaginians set down some roots in Massilia (Not to mention in Murcia as well).
English words that bear some resemblance to the above:
'mar' - to ruin or blemish
'mark' - a trace, sign, or scar on a surface
'march' - to walk in a military manner
'mercenary' - a hired soldier in foreign service (for reward)
And mark, Mercia, the Marches, March is a boundary: a starting-and-stopping.