Complex sentence: Once Belgium had claimed its independence from the Netherlands in 1830 the treaty of the Scheldt determined that the river should remain accessible to ships heading for Belgian ports, nevertheless, the Dutch government would demand a toll until 16 July 1863.
Split into simpler sentences: Once Belgium had claimed its independence from the Netherlands in 1830 the treaty of the Scheldt determined that the river should remain accessible to ships heading for Belgian ports. Nevertheless, the Dutch government would demand a toll until 16 July 1863.