Original: Holyrood Abbey was founded by David I, King of Scots in 1128, and Holyrood Palace has served as the principal residence of the Kings and Queens of Scots since the 15th century.
Simplified: The Palace of Holyroodhouse, or informally Holyrood Palace, founded as a monastery by David I of Scotland in 1128, has served as the principal residence of the Kings and Queens of Scotland since the fifteenth century.