Complex sentence: Land in the polders was state-owned during the entire developmental process, but several years after this was completed the various plots were distributed among private parties, with priority given to the early pioneers who had been in the polder since the start.
Split into simpler sentences: Land in the polders was state-owned during the entire developmental process, but several years after this was completed the various plots were distributed among private parties. Priority to the early pioneers who had been in the polder since the start.