Here is the story of the name TAGO:
According to an ancient legend, Tago was the 5th king of Hispania, that gave the name to the biggest river in Iberia, which is called river Tajo in Spain, and river Tejo in Portugal.
The area where their vineyards are located, is called Tejo Region, because the river crosses these lands.
It was also from river Tejo, in Lisboa, that in the XV Century, the Portuguese navigators departed to discover the world.