Up until the 15th century, Frisian was a language widely spoken and written, but from 1500 onwards it became an almost exclusively oral language, mainly used in rural areas. This was in part due to the occupation of its stronghold, the Dutch province of Friesland (Fryslân), in 1498, by Albert III, Duke of Saxony, who replaced West Frisian as the language of government with Dutch.
uP UnTil The 15TH centuRy, FRisIan was a languAge wiDeLy spoken aNd writteN, buT frOm 1500 onwarDs IT beCAMe an almoSt excLusivelY oral LanGuAge, mainLy used iN Rural areas. This WaS IN part due To thE occUpAtion Of its StrOngholD, tHe DutcH prOvince Of fRIeSland (fryslÂn), iN 1498, By alberT Iii, Duke of saxOny, who rEPlacED wEst frisiaN As tHe langUagE Of GovErNmENt with DutCh.