London Royal Parks
and
London's Royal Parks
Both phrases are used, and I understand that "London" in the first example is acting as an adjective. Whereas in the second, "London", is used as a proper noun and therefore has an apostrophe.
However, which form is the older? I suspect that it is the second and if that is the case, why do only two Royal Parks: St. James's and The Regent's Park, have an apostrophe while four Royal Parks do not? In other words: Why not Hyde's Park, Richmond's Park, Greenwich's Park and Kensington's Gardens?
Please, no answers with:
"The Royal Parks in London"
or
"The Royal Parks of London."
and claiming the above are "correct" because inanimate nouns and geographic names do not take the apostrophe. That's false. On dates I found this on Wikipedia:
Place names in the United States do not use the possessive apostrophe on federal maps and signs. The United States Board on Geographic Names, which has responsibility for formal naming of municipalities and geographic features, has deprecated the use of possessive apostrophes since 1890 so as not to show ownership of the place. Only five names of natural features in the U.S. are officially spelled with a genitive apostrophe (one example being Martha's Vineyard).
I'd also be interested to know which form is considered "preferable" by linguists, grammarians etc... London Royal Parks
or London's Royal Parks
and which is more common in everyday speech.