Lord Horatio Nelson was giving orders 30 minutes after his arm was amputated, according to journals in the National Archive that illustrate the importance of medical skill in securing Britain's naval might.

A collection of 1,200 naval journals, not seen for 200 years, depicts the horror of life on board British fighting vessels in the 18th and 19th centuries, including details of the medical treatment given to Nelson.

Researchers at the National Archives in Kew have gathered personal accounts written by surgeons at sea, revealing some of the first scientific investigations into diseases such as scurvy.

Among the documents, reported in The Independent, is a handful of journals describing the remarkable speed and skill with which medics nursed Nelson back to health from surgery – twice.

It is claimed that within 30 minutes of having his right arm cut off, Nelson was again issuing orders to his men. He had been hit in the right arm by a musket ball shortly after stepping ashore on the Spanish island of Tenerife in July 1797.