Looking for translation of phrase ある　おしろに


I understand that ある means to live / to be. But I'm having trouble finding the
purpose or translation of おしろに. I wonder if these two are working together to
create some kind of meaning. It's from a children's book. The first line is
むかし、(once upon a time), followed by the text above. My interpretation is that
this means something to the effect of, "Once upon a time, there lived...". But
I'm not understanding the specific action of the おしろに part of the sentence and
so far haven't had luck with the dictionary. Any help is appreciated.




Before getting to おしろに, I'll talk about ある. The verb ある that you're thinking
of means "to be / exist" but it's generally not used for living things. So it
usually wouldn't mean "to live." Here it's not a verb, but a (probably
etymologically related but different) ある that can only go before a noun and
means "a certain ~"

As for おしろに, the core of it is しろ (castle).

In front of the core it has a kind of honorific / word-beautification marker
お.

At the end is the location-marking particle に.

If we put everything together, あるおしろに means "in a certain castle."

Presumably the sentence continues with a description of someone living in the
castle.




Before getting to おしろに, I'll talk about ある. The verb ある that you're thinking
of means "to be / exist" but it's generally not used for living things. So it
usually wouldn't mean "to live." Here it's not a verb, but a (probably
etymologically related but different) ある that can only go before a noun and
means "a certain ~"

As for おしろに, the core of it is しろ (castle).

In front of the core it has a kind of honorific / word-beautification marker
お.

At the end is the location-marking particle に.

If we put everything together, あるおしろに means "in a certain castle."

Presumably the sentence continues with a description of someone living in the
castle.

