Question: When was the last super bowl the redskins won?

Disambiguated questions and answers:
context: All of the Redskins' league titles were attained during two 10-year spans. From 1936 to 1945, the Redskins went to the NFL Championship six times, winning two of them. The second period lasted between 1982 and 1991 where the Redskins appeared in the postseason seven times, captured four Conference titles, and won three Super Bowls out of four appearances. The Redskins have also experienced failure in their history. The most notable period of general failure was from 1946 to 1970, during which the Redskins posted only four winning seasons and did not have a single postseason appearance. During this period, the Redskins went without a single winning season during the years 1956–1968. In 1961, the franchise posted their worst regular season record with a 1–12–1 showing. Since their last Super Bowl victory following the end of the 1991 season, the Redskins have only won the NFC East three times with just nine seasons with a winning record. In those, the team only made the postseason in six of them.
question: What is the date of the last super bowl the redskins won?
short_answers: 1991
wikipage: Washington Redskins
context: The 1991 season started with a franchise-record 11 straight victories. Also during the season, "The Hogs", under the coaching of Redskins offensive line coach Joe Bugel, allowed a league low and franchise record nine sacks – the third lowest total in NFL history. The 1991 Redskins offense also dominated under the brilliant coaching of offensive minded head football coach Joe Gibbs scoring 485 points which was the most by any team in the 1991 NFL season. The 1991 Redskins defense was also dominant under the coaching of defensive coordinator and guru Richie Petitbon, giving up only 224 total points which was second best of any team in the NFL in 1991, while also not allowing a single point to opponents in 3 of the 16 games played that season. After posting a 14–2 record, the Redskins made and dominated the playoffs, beating the Falcons and Lions by a combined score of 64–17. On January 26, 1992, the Redskins won Super Bowl XXVI by defeating the Buffalo Bills 37–24 with Mark Rypien winning the games Super Bowl MVP award. After the Super Bowl, the Redskins set another franchise record by sending eight players to the Pro Bowl. The 1991 Washington Redskins are widely considered one of the best teams in NFL history.
question: What is the number of the last super bowl the redskins won?
short_answers: XXVI
wikipage: Washington Redskins

Long-form answers:
knowledge: content: The Washington Football Team is a professional American football team based in the Washington metropolitan area. Formerly known as the Washington Redskins, the team competes in the National Football League (NFL) as a member club of the NFC East division. 
wikipage: Washington Football Team
content: Since the 1991 season, when the team last won the Super Bowl, they have won the NFC East four times, had a winning record in nine seasons, and reached the postseason in seven.
wikipage: Washington Football Team
content: The Redskins won their second championship in Super Bowl XXII on January 31, 1988, in San Diego, California.
wikipage: Washington Football Team
content: In January 1983, during the second round of the playoffs against the Minnesota Vikings, John Riggins rushed for a Redskins playoff record 185 yards, leading Washington to a 21–7 win. The game is perhaps best known for a moment when the stadium physically shook as a crowd chanted "We Want Dallas!", which later became a rallying cry of sorts for Redskin fans before games against the Cowboys.[31] In the NFC Championship Game against them at Robert F. Kennedy Memorial Stadium, Redskins defensive end Dexter Manley knocked Cowboys' quarterback Danny White out for the rest of the game and sent him into the locker room shortly before halftime. Later in the game, Redskins defensive tackle Darryl Grant's interception, which he returned for a 10-yard touchdown, off one of Cowboys' backup quarterback Gary Hogeboom's passes which was tipped by Dexter Manley to score the decisive points. John Riggins rushed for 140 yards and two touchdowns on 36 carries and the Redskins went on to defeat the Cowboys' by a score of 31–17.[30] The Redskins' first Super Bowl win, and their first NFL Championship in 40 years, was in Super Bowl XVII, where the Redskins defeated the Miami Dolphins 27–17.[9] 
wikipage: Washington Football Team
long_answer: The Redskins are a professional American football team based in the Washington metropolitan area that compete in the National Football League as a member of the NFC East Division. The team won its first Super Bowl in January 1981 and its second in January 1988. The most recent Super Bowl that the Redskins won was Super Bowl XXVI in 1991. Since the 1991 season, they have won the NFC East four times, had a winning record in nine seasons, and reached the postseason in seven.