Complex sentence: The year 1860 marks the latest, but not the first, Indian arrivals in South Africa, because the Dutch had brough Malays and Indians to the Cape Colony in the 1650s and 1660s.
Split into simpler sentences: The year 1860 marks the latest, but not the first, Indian arrivals in South Africa. The Dutch, who were the earliest colonial power in South Africa, had brought Malays and Indians to the Cape Colony in the 1650s and 1660s.