Duke Albrecht I extended to the citizens of Delft permission to dig a canal to the Maas River
Date:
September 8, 1389
Duke Aelbrecht I of Bavaria granted the citizens of Delft permission to dig an open channel of 6 rod from the city to the Maas and thereby freely transport their goods, whereby he specified that they will construct bridges and dikes.
The canal met the Maas just to the west of Rotterdam, thus avoiding tolls there. The village that grew at the end of this canal became Delfshaven, that is, Delft's harbor.
Document:
OAD Inv. 99 charter no 5032