# Letters were delivered by the hand of couriers

"Couriers hand-delivered the letters" or "Courtiers gave the letters directly"

# Letters

You may need to use a word for written instructions that is more general than "letter" so that the reader does not think that these documents were about only personal matters.

# annihilate, kill, and destroy

"completely destroy"

# thirteenth day of the twelfth month

"day thirteen of month twelve"

# plunder

steal by force