To take this decision:
1. Netherlands must not already exist and you may not be the Papal State.
2. Primary culture must be Dutch or Flemish.
3. You must own and have core on Zeeland, Holland, Utrecht and Friesland.
Effects:
1. Change your country to Netherlands.
2. Grant cores on Vlaanderen, Breda, Zeeland, Holland, Utrecht, Gelre, Friesland, Limburg and Antwerp.
3. Gain +1 base tax in a random owned Dutch or Flemish-culture province.
4. Gain two points toward centralization.
5. Gain +5 prestige.
6. Gain +1 merchant.