The Khopesh was a Bronze Age sword from Egypt, meaning 'sickle-sword'. Two of these swords were found in the tomb of Tutankhamun. Date of this one pictured goes back to 3,000 BC and the ancient civilisation of Sumer. (Photographs of Bronze Age swords by Dbachmann.)
The weapon we recognise today as a sword dates from around 1600 BC. Interesting, to me, is that the word 'sword' came from an Anglo-Saxon word 'sweord'. The golden age of swords was definitely the Medieval period in Europe, although the influence of China and the Middle East is not without significance.
From around 5BC, the Bronze Age swords were replaced by weapons made from iron, at the start of the Iron Age. These swords also took on a different design and looked like the straight-bladed weapons we think of as swords today. The pre-Roman swords were known as Celtibarian, a name taken from the peoples known as Celts who lived in west Europe, in this instance the Iberian peninsula.
The Anglo-Saxon and and Viking swords were based on the Roman spatha. They were improved as new technology became available and then the Normans introduced the crossguard. But the Dark Ages swords will always be my favourites. Look out for my posts on individual swords, such as the Cawood sword, Goujan, Joyeuse and fictional ones from Lord of the Rings and Game of Thrones including my own design, Sunniva, Gulfyrian's sword.
The sword became a status symbol to many and thus they were subject to fashion trends and magnificent decoration. Even when their days of being the prime choice of weapon, swords continued to be made.