Complex sentence: Before encountering the British, Zulus first were confronted with Boers, for in an attempt to form their own state as a protection against the British, the Boers began moving across the Orange River northwards.
Split into simpler sentences: Before encountering the British, the Zulus first were confronted with the Boers. In an attempt to form their own state as a protection against the British, the Boers began moving across the Orange River northwards.