Jay Bee wrote:
Conemara has long been a proper noun
proper, so to speak. I grew up saying the Ukraine, the Lebanon, the Palestine, the Philippines, the US and the UK. The last three still stand, though many people now drop the article for the first three (however, I do hear
Americans...

) say
in US, in UK...
My feeling was that the first four were once, as territories or areas (as in
the Philippine Islands) part of a longer phrase that got clipped later on
Actually, that in mostly translationese. "The Ukraine" was a half-translation of the Russian for "the borderlands" (according to a BBC News web article I read earlier this year), and "the Lebanon" was derived from a Biblical name featuring the definite article (according to Wikipedia). I've never encountered "the Palestine" before, and Google isn't helping on that one.
It seems to be that there's four modern situations where the article is used with placenames: compound names with generic nouns as head (the United
Kingdom, The People's
Republic of China etc); plurals (the Netherland
s, the Himalaya
s; and rivers (the Liffy, the Amazon), forests (the Amazon) and deserts (the Sahara.
The plural rule clearly evolved out of the compound nouns rule (hence "the Philippine Islands" becoming "the Philippines"), but it seems like it's taken on a life of its own. Equally you could argue that the rivers and forests rules evolved by the same mechanism, although you'd need to look at old maps to prove it.
In the case of "the Congo", I'd speculate that the article has been borrowed in from the name of the river and/or the forest. The Sudan apparantly originates from an
Arabic name with the definite article, so that's translationese as well