Input (grade 12): Three years later, in South Africa during the Second Boer War, Baden-Powell was besieged in the small town of Mafeking by a much larger Boer army (the Siege of Mafeking).
Output (grade 10): Three years later during the Second Boer War, Baden-Powell was besieged in the small town of Mafeking by a much larger Boer army (the Siege of Mafeking).