Charles V (or Charles I of Spain) (24 February 1500 – 21 September 1558) was ruler of the Burgundian Netherlands (1506-1555), King of Aragon (1516-1556), King (until 1555 on behalf of his mother the queen Joana I) of Castile (1516-1556), King of Naples and Sicily (1516-1554), Archduke of Austria (1519-1521), King of the Romans (or German King), (1519-1556 but did not formally abdicate until 1558) and Holy Roman Emperor (1530-1556 but did not formally abdicate until 1558). In Spain, though he is often referred to as Carlos V or Carlos Quinto, he ruled officially as Carlos I, Charles I of Spain.
He was the son of Philip of Burgundy and Joanna the Mad of Castile. His paternal grandparents were Emperor Maximilian I and Mary of Burgundy whose daughter Margarete of Austria raised him. His maternal grandparents were Ferdinand II of Aragon and Isabella I of Castile, whose marriage had first united their territories into what is now modern Spain, and whose daughter Catherine of Aragon was Queen of England and first wife of Henry VIII. His cousin was Mary I of England who married his son Philip.
Charles V's reign introduced the first documented use of the styles of His Majesty or His Imperial Majesty. Because of his far-reaching territories he was described as ruling an Empire "in which the sun does not set".