The Euro was launched, as an electronic currency only, on 1st Jan 1999. When trading began on 4th Jan, after the holidays, it was worth $1.18. The Euro became legal tender on 1st Jan 2002 at which time it was worth, during that day, an average of $0.9050.
i thought i'd read a previous answer to a similar question on this site that said that the initial value of the Euro was set at $1 exactly. maybe i'm mistaken. it would seem unlikely that its value would rise 18 cents in 3 days (assuming mikewall is right and i've no doubt he is)