The term "katana" specifically refers to the curved, single-edged swords that emerged during the medieval period in Japan. The oldest surviving katana swords typically date back to the Kamakura period (1185-1333) or later. However, it's important to note that the specific age and origins of the oldest katana can be challenging to determine due to the passage of time and the scarcity of well-preserved ancient swords.

The katana's development and refinement took place over centuries, and earlier swords, such as the tachi, were precursors to the katana. These tachi swords were used by samurai during the Heian period (794-1185) and featured a similar curved blade design. Some surviving tachi swords from this period can be considered among the earliest examples associated with the development of the katana.

Archaeological discoveries and historical records contribute to our understanding of the earliest katana swords, but definitive information about the absolute oldest katana is difficult to ascertain. The age and origins of ancient swords can be influenced by factors such as the passage of time, preservation conditions, and historical documentation.