The Cubs and White Sox are bitter Windy City rivals, and at times that frosty relationship on the field has led to a distinct lack of communication between their two front offices.

Every now and then, however, the crosstown foes have reached a detente and agreed to a trade. The latest editions came in 2021, when the Cubs and White Sox made multiple deals, including a blockbuster. First, the Cubs sent right-handed reliever Ryan Tepera to the Sox in exchange for Minor League left-hander Bailey Horn. But the big move came on Deadline day, when the Cubs sent star closer Craig Kimbrel to the White Sox for second baseman Nick Madrigal and reliever Codi Heuer.

That marks 30 trades between the two Chicago teams across their long histories. Here's a look back at some of the most notable swaps:

July 30, 2021: Cubs trade Craig Kimbrel to White Sox for Nick Madrigal and Codi Heuer
Kimbrel was the top reliever on the market leading up to the 2021 Trade Deadline, and the White Sox built a super-bullpen by landing the veteran closer from the Cubs.

The White Sox already had arguably the best closer in the league, Liam Hendriks -- an All-Star and the AL saves leader with 25 at the Deadline. Pairing him with Kimbrel, who had 23 saves and a 0.49 ERA, gave the White Sox an unrivaled two-headed monster at the back of their bullpen. And that's not even getting into the rest of their deep relief corps, with Michael Kopech, Aaron Bummer, Tepera and more.

The Cubs netted a big return for Kimbrel, too. The former top prospect Madrigal could be a future star -- the 24-year-old was batting .317 over his first two big league seasons at the time of the trade -- and the hard-throwing 25-year-old Heuer is a potential relief ace.

July 13, 2017: White Sox trade Jos¨¦ Quintana to Cubs for Dylan Cease, Eloy Jim¨¦nez, Bryan Flete and Matt Rose
The crosstown rivals hadn't traded with each other in more than a decade, and then they pulled off a big one. The Cubs, eyeing another deep October push after finally ending their 108-year World Series title drought in 2016, picked up an extremely durable lefty workhorse in Quintana. The White Sox, planning their own resurgence, got back each of the Cubs' top two prospects to make this swap a legitimate blockbuster.

Quintana continued as a steady (if not spectacular) presence in the North Siders' rotation until he departed via free agency after the 2020 season. Jim¨¦nez busted out for 31 homers in his '19 rookie campaign, and he and Cease are now major cogs for a legitimate American League contender on the South Side.

"This notion that we wouldn't do business with them because they're in town, or somehow we would actually take an inferior baseball deal for non-baseball reasons -- because of emotion or a rivalry, or something totally unrelated to putting the best possible team on the field for the next several years, is frankly somewhat laughable," White Sox general manager Rick Hahn said of this swap with the Cubs. "If we really felt motivated to take an inferior baseball deal, to not put this organization in the best possible spot to win multiple championships simply because of emotion, then we would be the wrong people running this club."

July 29, 1998: White Sox trade Matt Karchner to the Cubs for Jon Garland
Garland was a first-round pick by the Cubs in the 1997 Draft, but they traded him a year later in a Deadline deal for the reliever Karchner as they geared up for a playoff push. The Cubs did win the Wild Card, their first playoff appearance since 1989, but Karchner struggled, with a 5.14 ERA in 29 appearances for the Cubs that year.

Garland, meanwhile, went on to become a franchise mainstay on the South Side. He pitched his first eight seasons with the White Sox in a 13-year career. He was a key member of the starting rotation for the 2005 team that ended the franchise's 88-year World Series drought, going 18-10 with a 3.50 ERA, making the All-Star team and finishing sixth in American League Cy Young voting. In two postseason starts, Garland threw a complete game to beat the Angels in the ALCS and went seven innings in a win over the Astros in the World Series.

March 30, 1992: Cubs trade George Bell to the White Sox for Sammy Sosa and Ken Patterson
In exchange for the veteran outfielder Bell, the Cubs got one of the most powerful sluggers to ever play the game. Sosa was just 23 years old when he played his first game for the Cubs, but he would go on to crush 545 home runs in 13 seasons with the team. That included 66 in 1998, when Sosa lost the memorable home run race to Mark McGwire but won the NL MVP trophy. Sosa was a seven-time All-Star and six-time Silver Slugger with the Cubs, leading the league in homers twice and hitting 40 seven times.

Bell was a former MVP and coming off an All-Star season with the Cubs at the time of his trade to the White Sox. But he ended up playing only two more seasons on the South Side before retiring in 1993, as he struggled through knee injuries.

January 25, 1983: White Sox trade Steve Trout and Warren Brusstar to the Cubs for Scott Fletcher, Randy Martz, Pat Tabler and Dick Tidrow
This was the largest trade between the two clubs by total number of players. Trout ended up having the main impact among those involved, as he was a member of the Cubs' rotation in 1984 that helped the Cubs make the playoffs for the first time in 39 years. Trout went 13-7 with a 3.41 ERA in 32 games for the '84 Cubs. He won Game 2 of the NLCS against the Padres with an 8 1/3 inning, two-run effort and pitched 2/3 of an inning in relief in Game 5.

December 11, 1973: Cubs trade Ron Santo to the White Sox for Ken Frailing, Steve Stone, Steve Swisher and Jim Kremmel
Santo was on the tail end of his Hall of Fame career, but he was still a nine-time All-Star and five-time Gold Glover who had played all 14 of his Major League seasons with the Cubs at the time of his trade to the South Side. He had made the Midsummer Classic in each of his last three years with the Cubs.

Earlier that year, Santo had become the first player to use 10-and-5 rights to block a trade, which would have sent him to the Angels. With the third baseman's preference to remain in Chicago, a deal was worked out with the White Sox. Santo retired at age 34 after one season with the Sox.