The first written mention of the historical province of Tavastia is found in the Chronicle of Novgorod, in reference to a military campaign launched by Prince Vladimir in 1042.

The region had been ruled by the Swedes since the late 13th century, when Birger Jarl led the Second Crusade against the inhabitants of the historical province of Tavastia.

The north-eastern part of the province belongs to the so-called Hauho route, whose waters flow into Vanajavesi through Pälkäne and Valkeakoski.

In the southwestern part of the province, Lake Loimijoki rises in the Tammela and Forssa areas and flows through Loima and Huittisten into Kokemäenjoki.

In Riihimäki and the southern part of Lope, the headwaters of River Vantaanjoki flow south into the Gulf of Finland.