Who is Major Ernest Pettigrew from Major Pettigrew's Last Stand: A Novel and what is their importance?

Major Ernest Pettigrew is a 68 year old widower living in Edgecomb St. Mary. Major Pettigrew served with the Royal Sussex during his time in the military. Pettigrew's father was a colonel in the military and served directly with the Maharajah in India. The Pettigrews cherish their pedigree. Major Pettigrew also served in India but did not attain the same rank or status as his father.