Flag Act 1687

The Flag Act 1687 (An act to provide for the flag of the Principality of Whales; 1687:002-M) is an Act of the House of Nobles of the Viceroyalty of the Two Martyrs. It set out a new flag for Whales (See Flag of Whales) The Act was made in preparation of the entry into force of the Constitution of Whales the following year.

It was a controversial act. The Lord of Szandoh declared a "Jihad to be waged against Karl Battenberg and his lineage down to the tenth generation of their descendants for the total eradication of all proponents of that flag"