I'm looking for information regarding what I perceive as a disparity between the gender and article use in the names and related terms of some countries, and I'm hoping someone may be able to explain the reasons for the linguistic phenomena I'm seeing. In particular, though the issue may be more widespread, I'm noticing the issue with regard to two countries: Andorra and Australia (Andorre and Australie).
From observing various French publications on these countries, including news articles and Wikipedia entries, the two names share something which is confusing to me.
Both countries' names are, to the best of my knowledge, feminine. Both countries' names also tend to make use of a definite article, as such: l'Andorre, l'Australie. Thus, we have phrases such as Gouvernement de l'Australie. Yet the long form name of each country seems to inexplicably do away with the article: Principauté d’Andorre and Commonwealth d’Australie. To my understanding, the d' contraction can be used for de, which would only be used by dropping the article, or du, which would imply masculinity.
I could understand if there was a special case for the names of states or the like; however, there are examples in which this does not happen: India, for example, remains République de l'Inde in its full form.
Could someone please explain why this is happening? Why would one use Commonwealth d'Australie for a country name which is feminine and seemingly otherwise preceded by an article?
(On a potentially unrelated note, while writing this I came across this article on the premiership of Australia, which likewise uses the d' contraction in its title; yet, further down the page, we see the heading Liste des Premiers ministres de l'Australie - which uses de l' instead. Is this the same issue?)