Nathaniel Blackerby (16..?-1742), served as Clerk of the Patent, a mid-level official at the Exchequer, but also held other positions including Treasurer to the Commission for Building Fifty Churches, where he worked closely with Nicholas Hawksmoor (1662-1736), the Commission’s Principal Surveyor. They were jointly responsible for signing completion certificates, with Blackerby disbursing funds thereafter. In 1726, William Cowper appointed Blackerby Housekeeper in Ordinary at Westminster Palace, a position in his gift.

Like Cowper, Blackerby was a member of the Horn Tavern Lodge in New Palace Yard. He was also a member of Grand Lodge, serving as Grand Warden in 1727, Deputy Grand Master in each of the following two years, and appointed Grand Treasurer of the Charity Bank, the first to hold that position. Blackerby promoted freemasonry avidly and in 1729 and again in 1730 wrote the prologue and epilogue for plays performed at the Theatre Royal in Drury Lane in front of a predominantly Masonic audience:

Blackerby was also a London magistrate and, following Cowper’s resignation as chair of the bench in 1727, was nominated as his successor. However, ‘after a Letter… intimating his Desire of being excused the chair’, Leonard Streate, another member of the Horn who had chaired the bench in 1725, was ‘unanimously chose’. Blackerby’s judicial activities were reported extensively in the press with several hundred news items appearing over the course of his career.

In 1738, shortly after becoming Deputy Lord Lieutenant for Middlesex, Blackerby was nominated to chair the Westminster bench once more. He accepted and his speech to the Westminster Justices was similar in tone to William Cowper’s some years before. Blackerby reminded his audience that duty, liberty and property were fundamental to society:

the Cause you are engaged in, is the Cause of your God, your King and your Country… consider the Duty you owe as Subjects to your King, under whose mild Government, and wise Administration, every Man enjoys the Fruits of his Labour, his Liberty, his Property.