Complex sentence: This was followed by Oldenzaal, Ootsmarsum and finally Lingen were all taken by the end of 1597 which meant that most of the Netherlands had been recaptured and a significant barrier created.
Split into simpler sentences: This was followed by Oldenzaal, Ootsmarsum and finally Lingen by the end of the year. The offensive success meant that most of the Netherlands had been recaptured and a significant barrier created.