Can I replace "Sire" with "Your highness" here?
Native speaker’s answer
Rebecca
Yes, you can! These two terms are fairly interchangeable since you are addressing a man of a higher rank or royalty, such as a king. Using "your highness" or "sire" is a way to show respect and formality towards a king. You would not say "sire" to a queen or a lady of high social ranking. You would use "My lady" or "Madam." However, you can still use "your majesty" or "your highness" to address a queen. Ex: Your highness, you have an important meeting in the throne room. Ex: Please stand as your highness enters the room.