I need help finding a book that I can't find
It is about a prince who reincarnates into a fantasy as the first prince of one of the 4 kingdoms. All I know is that there is a dwarf kingdom, a elf kingdom, and two human kingdoms. But he is in the only human kingdom in which the system is very matriarchal and he is first prince ever. But he also has a system to help him. He also has 7 in training soldiers.