Initially this plaque looked like it was raised by a man simply concerned about his property.
The only notable Warburton we could find in the area is a Dr Warburton who managed the insane asylum which took over Pembroke House after Thomas Braidwood's school for the deaf had moved out. It then became known as Dr. Warburton's House. This was on the site of what is now the Bayford Street Industrial Centre, about a mile to the north of the plaque. We struggled to link our J. A. Warburton to Dr Warburton and were beginning to think there was no connection.
Then at Studymore (packed with facts about the lunatic asylums of Hackney) we found our man. This gives his first names and dates and explains that he inherited 3 lunatic asylums from his father John (d.1845), via his brother, Thomas, who only survived their father by 2 years. At one stage the family home was in Exmouth Place, backing onto Pembroke House.
Studymore also led us to British History Online which explains: By marriage a Thomas Warburton acquired a lunatic asylum, Whitmore (formerly Balmes) House. "The asylum passed to Thomas's son Dr. John Warburton (d. 1845) and was closed in the mid 19th century, although more crowded madhouses in Bethnal Green remained in the family. A house which Thomas held from 1801 in Mare Street was to be demolished in 1847 and was commemorated in Warburton Road."
The grandfather Thomas (d.1836) purchased the Bethnal House Asylum in 1800. This is the one alongside the plaque erected by his grandson proclaiming his ownership.
At the Monumental Inscriptions of Middlesex we found the family's dates. Dr John Warburton died 2 June 1845, aged 52. His eldest son Thomas died 2 February, 1846, aged 24. John Abernethy died 12 December, 1850, aged 25. Very early deaths for both sons. Possibly running a string of lunatic asylums was not good for one's health.