The oldest known bronze sword that has been discovered to date is the "Naue II" sword, named after its typology classification. The Naue II sword is a style of bronze sword associated with the Bronze Age and was in use during the second millennium BCE.

The Naue II swords were developed in the Aegean region, specifically in what is now modern-day Greece. They were characterized by a long, slender blade with a pronounced mid-rib and a hilt that included a pommel and a guard. The sword had a symmetrical design, making it suitable for both thrusting and slashing attacks.

Some notable examples of Naue II swords have been found in archaeological sites such as Mycenae and Troy. These swords are estimated to date back to around 1600-1400 BCE, placing them among the oldest bronze swords discovered so far.

It's important to note that archaeological discoveries continue to provide new insights into ancient weaponry, and there is always the possibility of older bronze swords being unearthed in the future. However, as of now, the Naue II sword is widely regarded as one of the oldest known bronze swords.