Leahy and Blaquiere were the army agents based in Dublin at 49 Dawson Street. There was very little information on Leahy in the available records many of which were destroyed in the fire at the Four Courts in 1922 whereas some of the biographical details were available on his partner, Blaquiere.
I believe the signatures on the letter of 28 July 1801, to be those of Edward Leahy and Peter Boyle Blaquiere. Blaquiere’s father was the descendant of a noble Frenchman who emigrated from France and settled in London originally. In 1772 his fifth son Lieutenant Colonel John de Blaquiere was appointed Chief Secretary to the Lord -lieutenant of Ireland.

Peter Boyle Blaquiere, the surname on the letter, was born in 1784 being the grandson of this French émigré.
Interestingly, he served in the Royal Navy as a midshipman on the ‘Director’ commanded by none other than the most infamous of sailors, Captain Bligh of the Bounty fame.
During this most famous mutiny, Captain Bligh, Blaquiere and two other midshipmen were forced off the ship onto a small boat. Blaquiere was one of the lucky ones as he survived the incident.
Apart from the Bounty Mutiny very little is known of Blaquiere’s early life at this time.

However, during recent research I came across records in the Killadoon Papers, which revealed interesting snippets on Leahy’s and Blaquiere’s partnership as agents. The papers confirmed that both Leahy and Blaquiere were indeed army agents but astonishingly proclaimed that Leahy was the bastard son of Peter Boyle Blaquiere’s father.
In actual fact, these two gentlemen were half brothers.

In 1799-1804 letters and papers of Lord Clements (Lord Leitrim), recorded a dispute over regimental matters, leading to a crown prosecution of the agent Edward Leahy, the illegitimate son of Lord Blaquiere.
Peter Boyle Blaquiere became Leahy’s executor as Leahy had died 26 August 1803, intestate and unmarried.
As Edward Leahy was an illegitimate person, administration of the Leahy estate was granted to Peter Boyle Blaquiere. Unfortunately, a dispute arose between Lord de Blaquiere and his son Peter, over major legalities.

The records also revealed that Peter Boyle Blaquiere lodged all Leahy’s monies in his bank account which Lord Blaquiere claimed as his own. Accusations ensued continuously requiring the son having to employ legal assistance to defend himself.
Years later in 1812, the government indicated that Peter Boyle Blaquiere was accountable for all monies that Leahy received. These monies were directly related to the various regimental funding.
In conclusion, the government granted all property, of which Edward Leahy died possessed of, to Lord Blaquiere and his heirs.

Through time, Peter Boyle Blaquiere moved to Canada to establish a position for himself amongst the gentry. In 1839 he became a legislative councillor for the United Province of Canada.
Peter Boyle Blaquiere died 1860, in Canada at the age of 76 years.

In the National Archives Dublin, a search of some surviving records of the Military Department of the Office of Chief Secretary for Ireland, unearthed the name of Edward Leahy in the “minutes” (summaries of important letters issued 1813) of the Civil Department of the Office of Chief Secretary.
It was a précis of a letter to the Honourable P.B. Blaquiere, concerning the proposed appointment of a Tidewater or Customs Official at Dublin Port.
As stated previously nearly all official documents of Leahy and Blaquiere were destroyed in 1922. Only a few survived the fire.

Apart from the connection to the Leahy and Blaquiere relationship, the most startling and intriguing episode in the life of Peter Boyle Blaquiere was certainly the incident of The Bounty Mutiny.

The Leahy and Blaquiere letter (Private Collection)
National Archives Dublin
Dictionary of Canadian Biography
Wilson’s Dublin Directory for the year 1801
Transcript of the letter dated 1801
Parliamentary Papers Extract
The Killadoon Papers (NL)