Oostwaard is named after the "Heerlijkheid" Oostwaard, which is located on the river Vecht near Utrecht. A Heerlijkheid was the basic administrative and judicial unit in rural areas in Dutch-speaking lands before 1800. It originated in the feudal subdivision of government authority in the Middle-Ages and was the precursor to the modern municipality system in The Netherlands. A Heerlijkheid could be bought and sold.

The Heerlijkheid Oostwaard originated as a medieval property of the Convent of Oudwijk, which after 1217 enjoyed protection from the Pope and the Bishop of Utrecht. After The Reformation, Oostwaard first belonged to the Staten van Utrecht, and it was later was sold to a private individual.

From the 19th century, title to the Heerlijkheid was transferred by decent and it is now owned by the family Van Holthe tot Echten.

One of the property rights that is associated with the Heerlijkheid Oostwaard which is still in existence are fishing rights (visrechten). Oostwaard Advocaten actively helps preserve these rights.  

The coat of arms of the Heerlijkheid Oostwaard  

The coat of arms of the Heerlijkheid Oostwaard is a swan, the symbol of purity, and has been in use since the 18th century.

The signature in the logo of Oostwaard Advocaten