Damascus is the capital city of Syria and has been inhabited for over 10000 years. The city was featured prominantly during the Crusades and also known for the production of high quality swords made from the coverted Damascus steel from between 100 and 1700.
Damascus Steel (metal)
The actual process has been lost and attempts to recreate the process have been very variable with some reproducing the pattern and others similar properties. There is some current research indicating that small amounts of vanadium in the original ore (which is now depleted) may have contributed significantly to the quality of the steel.
There are a number of reproduction steels that appear similar superficially but actually are more cosmetic that any real attempt to recreate the steel despite being labelled as such (e.g. pattern-welded swords that are then acid etched are sometime sold as Dasmascus blades). Damascened steel is another term for the same process.