Crest: In a ducal cornet an oak tree fructed and penetrated transversely in the main stem by a frame saw. 
Proper, the frame Or.
It is erroneous to call the House of Hamilton a clan, it is a Scottish family who held territories in South Scotland including the Isle of Arran. They descend from Walter fitz Gilbert a Norman comrade of Robert the Bruce. They are second to the royal House of Stewart and are related to it. Their principle title is the Duke of Hamilton. They first appear on the Ragman Rolls of 1296 under the name Walter FitzGilbert of Hameldone although who he was is not certain.


He became Baron of Bothwell Castle granted by Robert the Bruce after the battle of Bannockburn and further gained the lands and barony of Cadzow. This eventually became the town of Hamilton.
In 1346 they fought for David II at the Neville's Cross. The 2nd Earl of Arran was heir to the throne both of King James IV of Scotland and Mary, Queen of Scots . Through the fifteenth and sixteenth centuries they were loyal to and fought for the Scottish crown in the battle of Ancrum Moor 1545. The Earl of Arran's eldest son James, was a commander in the Scots Royal Guards of Fran├žois II of France. A possible suitor of the widowed Mary, he eventually lost his mind at the age of 26 and was confined for the remaining 47 years of his life.
The third son John was made Marquess of Hamilton in 1599 and was keeper of Edinburgh and Stirling Castles. His son James succeeded in 1604 to his Father's titles and in 1609 to his uncle's. Previously, in 1587 Earl of Arran's brother Claud had been made first Lord Paisley. Paisley had fought at the Battle of Langside, but descended in later years into insanity. His son James had been created Baron Abercorn in 1603, and in 1606 Earl of Abercorn, Lord Paisley, Hamilton, Mountcashell and Kilpatrick for his assistance to King James VI at the Union of the Crowns. Claud, Lord Paisley died in or around 1621 and his grandson inherited his Lordship of Parliament.  The Irish title came with significant property in Co. Tyrone, Ulster, and this branch of the family is now represented by James Hamilton, 5th Duke of Abercorn. 
The Hamiltons under the third Marquis of Arran supported King Charles I during the Civil War. The Marquess was made Duke of Hamilton in 1643. He was beheaded with his king in London in 1649. His brother, William Hamilton, 2nd Duke of Hamilton died from wounds received at the Battle of Worcester in 1651.
Hamilton Palace in Hamilton, South Lanarkshire, had been the family's seat from 1695. In the mid nineteenth century the family moved to Lennoxlove House in East Lothian, which remains the residence of the current Duke.