Is it in 800 AD or 1800 AD. Was it done in Rome? Was it done in India? What was the name of the surgeon?
Pre-19th century transplants are not well documented. The first possibly real human transplant was in India. It is unknown if it was successful or not:
The first transplants known to be successful occurred in the 16th century:
However, those were transplants from one part of the body to another in the same individual
The first between two individuals was in the 20th century:
In 1905, Eduard Zirm conducted the first successful transplant between two individuals. He transplanted the corneas of an 11-year-old boy into a Czech day laborer. That was the first successful human transplant between two individuals that has been verified.