Ludwig Leichhardt disappears in 1848 while exploring central Australia in a second crossing attempt.

Leichhardt had again set out from the Condamine River to reach the Swan River.

The expedition consists of Leichhardt, four Europeans, two Aboriginal guides, seven horses, twenty mules and fifty bullocks.

The Europeans are Adolph Classen, Arthur Hentig, Donald Stuart and Thomas Hands, a ticket of leave holder who had replaced Kelly at Henry Stuart Russell's Cecil Plains station.

The Aboriginal guides are Wommai and Billy Bombat, from Port Stephens.

The party is last seen on April 3, 1848 at Allan Macpherson's station, Cogoon, on the Darling Downs. Leichhardt's disappearance after moving inland, although investigated by many, remains a mystery.

The expedition had been expected to take two to three years, but after no sign or word is received from Leichhardt it will be assumed that he and the others in the party had died.

The latest evidence suggests that they may have perished somewhere in the Great Sandy Desert of the Australian interior.