The political feud between Texas Gov. Rick Perry and his predecessor in the governor's mansion, former President George W. Bush, is the stuff of legend. Despite public denials from both men, "there's no question that there's tension between Bush world and Perry world," says Texas Tribune Editor-in-Chief Evan Smith. "The idea that there isn't is ludicrous to anybody that has been in the middle of Texas politics." At the same time, "getting anyone actually involved in Texas politics to talk about that tension — especially to a Washington reporter — would violate the first rule of the Perry-Bush fight club," says The Weekly Standard's Mark Hemingway. Still, there's plenty we do know. Here, some of the more credible episodes in the history of the Perry-Bush feud:

April 1995
Newly sworn-in Texas Gov. George W. Bush rejects Texas Agriculture Commissioner Rick Perry's suggestion to fill a vacant state appellate court slot with Perry's brother-in-law, Joseph E. Thigpen. Thigpen had served as district attorney in rural West Texas on and off since 1977, but was fired in 1993 for apparently being chronically unavailable when counsel was needed. This passing-over of Thigpen is "the still-beating heart of the rift" between Perry and Bush, says Will Weissert for the Associated Press.

Perry is running for lieutenant governor against popular Democrat John Sharp, and wants to run an attack ad. Bush and Karl Rove, with an eye toward the upcoming 2000 presidential election, are courting Sharp's voters to pad Bush's re-election margin and show broad popularity in the state. Rove threatens to withhold the endorsement of George H.W. Bush from Perry unless he ditches the ad; Perry complies, and barely squeaks out a win. "The Perry team blamed the Bush camp for not letting them air the ad," says Shushanna Walshe at ABC News. This is "when things got a little prickly" between the two sides.

December 2000
Perry takes over as governor when Bush resigns to become president. Perry does "nothing to improve relations by hastening the Bush family's exit from their living quarters," says Mark Barabak in the Los Angeles Times.

December 2007
Perry, stumping for presidential candidate Rudy Giuliani in Iowa, says of Bush: "George has never, ever been a fiscal conservative." He adds, "I mean, '95, '97, '99, George Bush was spending money." Ouch, "those are fighting words among Republicans — especially Texas Republicans," says Barabak in the L.A. Times, "and even more so to Bush loyalists who, years later, still simmer over Perry's off-the-cuff remarks." On top of the insult, "the Bushies hate it when Perry calls him 'George' in public," says Kevin Williamson at National Review.

Most of Bush's political circle — Rove, former President George H.W. Bush, James Baker, and top aide Karen Hughes, among others — back Sen. Kay Bailey Hutchison in her gubernatorial primary challenge against Perry. "It's hard to look at who endorsed Kay and not draw conclusions," says the Texas Tribune's Smith. "You have pretty much every consequential figure in Bush world" supporting Hutchison. Perry wins.

April 2011
Perry attacks two of Bush's key domestic achievements, the Medicare drug benefit and No Child Left Behind, at National Review. No Child Left Behind is "a cool name, but it's a monstrous intrusion into our affairs," Perry says of Bush's signature education law. "Look, I like George, but that's not good public policy." 

August-September 2011
Rove and other Bush allies criticize Perry for calling Federal Reserve Chairman Ben Bernanke "treasonous," and for labeling Social Security a "Ponzi scheme" and "monstrous lie." Rove calls the Bernanke attack "not, again, a presidential statement," and says Perry's Social Security views "are toxic in a general election environment and they are also toxic in a Republican primary."

Sept. 7, 2011
Perry returns the favor, saying in a Republican presidential debate that "Karl has been over the top for a long time in some of his remarks, so I'm not responsible for Karl any more."

Sources: ABC NewsAPLos Angeles TimesNational ReviewNew York TimesPoliticoWeekly Standard