Why did King George III ask the Parliament to enact the Proclamation of 1763?

The King issued the Proclamation of 1763 prohibiting settlements beyond the Appalachian Mountains

Explanation:

Colonists who had already settled on these lands were ordered to return east of the mountains. In 1765 Parliament passed the Quartering Act that said the colonists needed to find or pay for lodging for British soldiers stationed in America.

In response to Pontiac's Rebellion, a revolt of Native Americans led by Pontiac, an Ottawa chief, King George III declared all lands west of the Appalachian Divide off-limits to colonial settlers. This royal proclamation, issued on October 7, 1763, closed down colonial expansion westward beyond Appalachia.