After the expansion in the 14th century, the majority production moved to the central, Moravian Serbia. Vast patches of land were turned into the vineyards. In the 15th century, Constantine of Kostenets wrote: "many vineyards were planted, with such a great effort, in this country more than in any other", while De la Broquière noted that in the valleys of the Serbian state there are many villages and good food, and especially good wine. Turkish defters, after the Ottoman occupation in the mid-15th century, show how much the vineyards were spread and how much taxes were collected on wine and must. Fleeing from the Ottomans to the north, Serbs expanded the wine production in the area of Fruška Gora in Syrmia, which was a wine-producing region since the Roman period.