The estate of Drumry passed into the Hamilton's
possession in 1526 when Sir James Hamilton of Finnart married Margaret Livingston.
Sir James was the son of the Earl of Arran, and was brought up in the royal court. He attained many offices in the court including King James V cupbearer and architect to the crown; he helped design the palaces of Falkland, Holyrood and Linlithgow. He killed the Earl of Lennox while he was a prisoner after the Battle of Linlithgow. It was probably this that made him want to exchange his newly acquired Drumry estate; it being so close to Lennox territory. So in 1530 he exchanged Drumry for the lands of Crawfordjohn with Laurence Craufurd of Kilburnie. He also swapped his lands in Law and East Wemyss. All of this exchanging was to be in vain. He lost favour with the king and was tried for the Earl's murder. He was executed in Edinburgh.
The next Earl of Arran, another James Hamilton, became regent of the young Queen Mary, after Cardinal Beaton was found having forged the late king's will to assume the regency for himself. The Earl agreed to Henry VIII of England's plan to marry his prince, Edward, with the young Scots Queen. In a change of heart common to the times he later opposed the deal. This move split the Scottish nobility. Cardinal Beaton, although a rival of Hamilton's, joined with him and Mary of Guise, the Queen Mother, to denounce the proposed union. They called for French aid, but when the ship arrived carrying money and arms to Dumbarton Castle, the Earl of Lennox captured the cargo on behalf of Henry VIII, who had promised him the regency in return for his support of the union. There followed much political manoeuvring, only to culminate in the Battle of Pinkie in 1547.
The Hamiltons were supporters of Queen Mary and a Hamilton is in possession of Drumry in 1575, although it returned to the Craufurds soon after. At the Battle of Langside, 6 Hamiltons of the Kilpatrick parish fought for Queen Mary.
Briefly later, a Hamilton was to become the laird of Garscadden during the rise of the Covenanters. Sir John Hamilton of Orbiston was in possession of Garscadden from 1638. He was a royalist and during the civil war he was taken prisoner in his own house by Oliver Cromwell's forces in 1651. The roundheads then marched on Dumbarton castle, and Cromwell's General Monk took the castle in 1652. The commonwealth troops granted Garscadden to a prominent roundhead, Robert Mure, in 1653.