John Harbaugh, left, and Jim Harbaugh became the first siblings to face each other as coaches in a major sports match-up on Super Bowl Sunday in 2013. Older brother John Harbaugh's Baltimore Ravens won over the San Francisco 49ers.
Famous sibling rivalries – Probably the biggest (fictional) brother vs. brother rivalry took place on the popular 1980s TV show "Dallas." Bad boy J.R. Ewing -- played by actor Larry Hagman, right -- squared off against his good-guy brother Bobby, played by Patrick Duffy.
Famous sibling rivalries – The good-vs.-evil brotherly battle between Marvel comics characters Thor (Chris Hemsworth), left, and Loki (Tom Hiddleston) was the core of "The Avengers."
Famous sibling rivalries – Noel and Liam Gallagher's tumultuous relationship still triggers tabloid headlines today, years after Noel -- the calmer half of the brotherly partnership -- quit the British band Oasis.