The Beltway Series, promoted by the teams as "The Battle of the Beltways," is the Major League Baseball (MLB) interleague rivalry series played between the Baltimore Orioles and Washington Nationals. The Orioles are a member of the American League (AL) East division, and the Nationals are a member of the National League (NL) East division. The series name is taken from the beltway highways, the Baltimore Beltway (I-695) and the Capital Beltway (I-495), that serve Baltimore, Maryland, and Washington, D.C., respectively. Unusually for a sports rivalry, it arises more from circumstances surrounding the history of baseball in the two cities, about apart yet considered different markets, than anything that has so far happened on the field between the teams. Washington's previous team, the Senators, had been AL regulars for most of the 20th century, but after their 1933 pennant often finished last or almost last in the standings. Within a decade of the AL St. Louis Browns' move to Baltimore to become the Orioles in the 1950s, the Orioles became pennant contenders while the Senators moved to Minnesota and became the Twins. A replacement Senators franchise fared little better either commercially or athletically, moving to Arlington, Texas and becoming the Texas Rangers within another decade. Following that move, Orioles' owner Peter Angelos strongly opposed any attempt by Major League Baseball (MLB) to expand to Washington despite that city's larger market, arguing that both teams would suffer commercially and that the Orioles' protected market had legally expanded to Washington once the second Senators franchise moved. After the former Montreal Expos moved to Washington for the 2005 season, the Nationals and the Orioles began a contentious business relationship over the Mid-Atlantic Sports Network (MASN) cable channel that carries telecasts of both teams' games, the only such arrangement in MLB. The Orioles own the majority stake, with the Nationals beginning in 2005 as a 10% partner and their stake increasing one percent per year for 23 years until reaching a cap of 33 percent. In the early 2010s the Nationals claimed that they were not getting their full share of MASN revenue; MLB's arbitration panel agreed with them but the Orioles, rather than accept that result, took it to court instead. History of the series When interleague play began in 1997, MLB identified the Philadelphia Phillies as Baltimore's interleague "natural rival," and the Orioles began an annual interleague series against the Phillies that