Complete the following sentence: Singh enlisted as a dafadar in 1852 and served as a soldier over 50 years. He received the Indian Order of Merit for having saved the life of Sir Robert Sandeman at Lucknow at the time of the Sepoy Mutiny of 1857. <unk> <unk> <unk> <unk> <unk> <unk>
II Anglo-Chinese War, he saved the life of Sir Charles MacGregor as well.