1971 Euro?

According to Wikipedia: "The euro came into existence on 1 January 1999."
So how come MT4 has historical data for EUR/USD all the way back to 1971?

Hi.
In late 1970 the EEC introduced a fixed exchange rate but no actual currency. Member states that signed up agreed to tie their own currencies to this new currency with limited permitted fluctuations. For a while both the existing national currencies and the new currency could be traded
In 1979 the ECU, European Currency Unit, an average of currencies taking part in the new Exchange Rate Mechanism, replaced this. There was stil no actual physical currency.
The 1991 Maastrict Agreement set 1999 as a target date for full monetary union and the launch of a new currency. UK opted out of this.
Jan 1999 the Euro came into being and other European currencies like the Franc, Punt, Lira, ceased.
Hope this helps

Thanks a lot, Carlos!