This is the 12439th most frequent Polish word.
naczelnemu
"To the chief" or "to the editor-in-chief" (dative form of "naczelny").
In this sentence, 'naczelnemu' is the dative form of 'naczelny', indicating the person to whom the documents were handed.
Przekazałem wszystkie dokumenty naczelnemu redaktorowi.
I handed all documents to the chief editor.
Here, 'naczelnemu' describes the position or role of the dog, indicating its leading status in the group.
Naczelnemu psu przypadła największa porcja jedzenia.
The leader dog received the largest portion of food.
In this instance, 'naczelnemu' refers to the chief status of the guard and uses the dative case to describe the recipient of the medal.