This was in part due to the occupation of its stronghold, the Dutch province of Friesland (Fryslân), in 1498 – when Duke Albert III, Duke of Saxony, replaced Frisian as the language of government with Dutch.
As late as 1599, the London dramatist Thomas Dekker could introduce whole scenes in the mixed Frisian-Dutch argot of the coast in The Shoemaker's Holiday, in confidence that his English-speaking audience could follow it.
In this period the great Frisian poet Gysbert Japix (1603–1666), a schoolmaster and cantor from the city of Boalsert, seen as the father of modern West Frisian literature and spelling, was an exception to the trend.
His example was not followed until the 19th century, when new generations of West Frisian authors and poets appeared.
This coincided with the introduction of the so-called newer breaking system, a prominent grammatical feature in almost all West Frisian dialects, with the notable exception of Súdwesthoeksk.