For over 50 years former retired unbeaten heavyweight champion Rocky “The Brockton Blockbuster” Marciano, 49-0, held that record retiring after his last fight in September of 1955. There have been other well-known boxers who retired besides by choice such as by injury or by death. When Ingemar Johansson knocked out champion Floyd Patterson Marciano went into secret training to bring the world title back to the US, but he just couldn’t return to the form that he had when he retired. He was inducted into the IBHOF in 1990. “I’m retiring because of my wife and baby. No man can say what he will do in the future, but barring poverty, the ring has seen the last of me. I am comfortably fixed, and I am not afraid of the future,” said Marciano.

Super Middleweight Joe “Pride of Wales” Calzaghe, 46-0 (32), of Wales, in the UK, came to the US for the first time in his career with a 44-0 record. He would defeat Bernard “The Executioner” Hopkins, 48-4-1, by split decision. Hopkins was not over the hill for he would go onto win world titles in the light heavyweight division after this defeat.

Calzaghe would end his career in his next fight defeating former world middleweight, light heavyweight and heavyweight champion Roy Jones, Jr., 52-4, in November of 2008 ending his career unbeaten. He would later claim the reason for his retirement was “the ring left my body wrecked! I have had more broken bones than I can remember. My hands are crippled. They ache every single day from all the breaks. I have a really bad back too. I’m on painkillers a lot and I’m going to have bad arthritis when I’m older,” said Calzaghe. He would be inducted into the IBHOF in 2014.

Middleweight Dmitry “The Grandmaster” Pirog, 20-0 (15), of Gelendzhik, Russia, in July of 2012 won the vacant WBO middleweight title stopping Danny “Miracle Man” Jacobs, 20-0. He would have three more title defenses before retiring in 2012 due to a debilitating back injury.

The WBA, WBO, WBC Minimum and IBF World Light Flyweight champion Ricardo “Finito” Lopez, 51-0-1 (38), of Mexico City, MEX, retired in September of 2001 with 24 title defenses. He would win in a rematch after a TD with Rosendo Alvarez. He announced his retirement in November 2002. He was inducted into the IBHOF in 2007.

IBF World and WBA Super World Super Middleweight champion Sven “Phantom” Ottke, 34-0 (6), of Karlsruhe, Germany, last fought in March of 2007. He had 21 title defenses. He was a 3-time Olympian in 1988, 1992 and 1996 with a 246-47-5 record. He was to make a comeback as a cruiserweight against Darius Michalczewski who pulled out.

European Middleweight champion Laszlo Papp, 27-0-2 (15), retiring in October of 1964. He was forced into retirement by Communist Russia when he refused to coach their Olympic team.

World Lightweight champion Jack “The Napoleon of the Prize Ring” McAuliffe, 28-0-10 (20), of Cork, Ireland and Williamsburg, NY, last fought in September of 1897 and was inducted into the IBHOF in 1995.

World Paperweight champion Jimmy “Little Tiger” Barry, 58-0-10 (39), of Chicago, IL, last fought in September of 1899. He was inducted into the IBHOF in 2000.

IBF World Super Lightweight champion Terry “Fighting Fireman” Marsh, 26-0-1 (10), of Basildon, Essex, UK, last fought in July of 1987. He was diagnosed an epileptic.

IBF World Super Bantamweight champion Ji Won Kim, 16-0-2 (7), retired after defeating Rudy Casicas, in June of 1986, to become a theatrical actor and singer.

WBC World Lightweight champion Edwin “Dinamita” Valero, 27-0 (27), of Merida, VZ, last fought in February of 2010. He was accused of killing his wife and hung himself while in his cell in April of 2010.