Simplify the following text for a Grade 12 native English-speaking person.
Original: The Royal Proclamation of 1763 was issued October 7 , 1763 , by King George III following Great Britain 's acquisition of French territory in North America after the end of the French and Indian War\/Seven Years ' War .
Simplified: The Royal Proclamation of 1763 was issued October 7 , 1763 , by King George III after Great Britain gained French territory in North America after the end of the French and Indian War\/Seven Years ' War .