In 1767, Henry Hawkins Tremayne married Harriet Hearle, the daughter of John Hearle of Penryn, acquiring in the process a third share of the extensive Hearle estates and mining industry.
In 1767, he married Harriet, the daughter of John Hearle of Penryn, a former vice-warden of the stannaries. As a consequence, he inherited a third share of the extensive Hearle estates and mining industry.