A letter penned by 19th century navigator Ludwig Leichhardt has been discovered by a Brisbane librarian more than 170 years after it was written.

The document gives an insight into the German-born explorer’s early life before he made his name in Australia.

Librarian Lynn Meyers from the Queensland State Library says she could not believe her eyes when she spotted the letter.

It was hidden inside a book of other material which was recently donated by a member of the Johnsonian Club.

“I was just astounded that it was there because the donor hadn’t mentioned it to me, so I was just flabbergasted,” she said.

In 1844, Leichhardt trekked nearly 5,000 kilometres from south-east Queensland to Arnhem Land in the Northern Territory.

But he is most famous for his fateful expedition four years later when he set out to cross the continent.

He and his small support team vanished with barely a trace.

Insight into early life

Queensland State Library content manager Gavin Bannerman says museums and libraries across the country have collected many letters by Leichhardt, but none date back as far the recent find.

“We have probably a million other letters in our collection but this one really stands apart because of who Leichhardt was,” he said.

The letter was written in German in 1839 and was found attached to a translation penned in 1887.

Ms Meyers says it gives an insight to Leichhardt’s early years while he was living in Paris, and tells of his friendship with the man who later went on to fund his expeditions.

“He was writing to John Nicholson, who was somebody he met at university,” she said.

“[He was] a rich Englishman who took Leichhardt under his wing and helped him survive.

“Leichhardt didn’t have very much money and Nicholson became one of his benefactors.

“Then he met John’s younger brother William Nicholson who also became his great friend and they lived together for many years when they were studying.

“So it provides a lot of information about that period of his life and these two important figures.”

The donated parcel of collected letters also includes a signed photograph of Thomas Edison.

All are now safely preserved inside the State Library.

Mr Bannerman says staff have spent years making the State Library collection world class.

“We’ve got Queen Victoria’s stockings,” he said.

“We recently acquired a collection that includes a tie worn by the Prince of Wales when he came to a ball.”