Grampa Abraham Simpson is the 83-year-old father of Homer Simpson. A veteran of WWII, he served in the Flying Hellfish squad along with C. Montgomery Burns and 7 others. Stationed in Germany, the unit captured a mansion full of priceless paintings. The Hellfish seized the paintings and agreed to a tontine, in which the last surviving member would receive the paintings. When only Grampa and Mr. Burns were left alive, Mr. Burns tried to assassinate him to get the paintings but failed. Mr. Burns was kicked out of the tontine, leaving Grampa with the paintings...until the descendant of their original owner came to the United States to claim them.
Abraham J Simpson was born on September 8, 1906. He was the second of five children born to Homey (1880-1959) and Deborah (1882-1978). He lived in New York City until he was 11. He had a sister named Debbie (1904-2000), another one named Anne-Marie (1909-2003), a brother named Homer (1912-1973) and a brother named Ethen, who was born on September 29, 1914 and died 22 hours later from childbirth. After Ethen's death, they had a son named Zandre-Ethan (1916-1945), who had cerebral palsy, was in a wheelchair from age 10 months until his death in January 1945. Zandre-Ethan or "Ethy" couldn't talk in his life. Since Ethy had so many challenges, he was homeschooled. On his birthday, June 15, they would not have cake. Ethy died in a car accident on January 12, 1945.
When he was a child, Abraham's family immigrated over to America, where they resided in the Statue of Liberty until they filled the head with garbage and had to move out.
Also during the war, Grampa had an affair with an Englishwoman named Edwina. Their love produced a child named Regina. Grampa also had a fling with a prostitute at a carnival. The baby they conceived grew up to be Herb Powell (1902-1990) , who founded a successful car company and lost it when he allowed his half-brother to design a car for it. Herb later regained his fortune with a baby translator.
Afterwards, Grampa met and married a woman named Mona, and they gave birth to a son: Homer Jay Simpson. Grampa has never been had faith in Homer's abilities, nor has he taken much interest in what he does. Even though he later sold a house so that Homer and his wife Marge could buy one, Homer stuck him in a retirement home three weeks later. His marriage to the rebellious Mona ended when she went underground in 1969 after sabotaging Mr. Burns' germ warfare laboratory. He told Homer that she died when the boy was at the movies, and the moss-covered grave he pointed out as hers actually belonged to Walt Whitman. She reappeared in Springfield twice before she died.
Today, Grampa is a bit senile and spends much of his time writing cranky letters and telling long, rambling, implausible stories. He is often considered a burden to the Simpson family and is taken for granted. But they are still capable of doing nice things for him. When his kidneys exploded after Homer denied him a chance to go to the bathroom while driving home from a ghost town, Homer donated one of his own eventually. Grampa also once inherited $100,000 from a woman he dated named Bea Simmons who passed away. He gave the money to charity and to make improvements in his retirement home. He was also briefly married to Selma Bouvier his son's sister-in-law.