Looking for information on John Hannan/Hannon/Hanan

According to the information on death certificate, John Hannan was born in Ireland in 1784 and his father’s name was Peter Hannan. John’s birthplace was Cavan, the main town in the county of the same name, north-west of
Dublin and not far from the border with Northern Ireland.

Married Mary Amberton in St Georges Church, Hanover Square, London in Dec 1825.

John’s death certificate shows that he was a Chelsea pensioner. Several references mention that John Hannan
fought at Waterloo.
At some stage in his early married life he was living at 4 Church Lane in London.

John joined the Royal New South Wales Veterans Corps formed in England in about 1825.

If any of this family info sounds at all familiar please contact me.

Thanks

Aussielost