The Holy See is the head of the Roman Catholic church, including the Pope.
It is recognized as having legal personality under international law.
The Holy See is legally distinguishable from the Vatican City, which is a territory over which the Holy See has sovereignty: some treaties the Holy See is a party to in itself, other treaties it is a party to in respect of the Vatican City.
However, the foreign embassies are credited to the Holy See and not to the Vatican State.
Generally, the Holy See as a party to a treaty reflects the interests of the Roman Catholic church, while Vatican City is generally only party to treaties which are not of general significance, e.g., treaties regarding co-operation with Italy.
Apart from Rome the episcopal see of Mainz is also called a holy see.
