Major Barclay Greenhill was born in 1820, the son of William Greenhill, and had one brother and two sisters: Charles, Emily and Harriet. He lived in St John’s Wood and worked at 35 Lincoln’s Inn Fields.

Greenhill was initiated 8 November 1860 amid the rush of enthusiastic support for the new Lodge by officers of the Regiment. This was the same Emergency Meeting that saw Major Whitehead join, and Henry Smith and William Rudge initiated as well, the day after they were proposed at the first Regular Meeting following the Consecration.

Barclay Greenhill was commissioned into the Victoria Rifles in 1858 alongside his future fellow Brethren Abraham Trew, William Collins and Charles Croft. He would go on to be promoted Major and command the Corps in 1870, notably for the Volunteer Review in Brighton.