DESIGNER MERRY-GO-ROUND: Stefano Pilati was out at Yves Saint Laurent and in at Ermenegildo Zegna. Versus, Azzaro and Vionnet lost their designers, and Jil Sander was back in at Jil Sander, after Raf Simons left that label for Dior. Nicolas Ghesquiere exited Balenciaga, the house he helped relaunch practically from the ashes after he took the helm as creative director in 1997. Less than a month later, Alexander Wang was named to replace him. Betsey Johnson went out of business in April — and now is reinventing herself under new parent company Steve Madden. (A year-long whirlwind.)

ONE-UPSMANSHIP: The scenery at runway shows now rivals that of Hollywood blockbuster productions. In 2010, Karl Lagerfeld set the bar high when he brought in a 265-ton iceberg from Sweden to use as a set for his Chanel runway show at Paris’ Grand Palais. Since then, it seems like designers have been trying to top that stunt — Lagerfeld included. In January, he built a life-size airplane to house his Chanel couture show in Paris. In March, Louis Vuitton’s Marc Jacobs countered with an $8-million steam train that rolled into a tent in front of Paris’ Louvre. In September, Kaiser Karl was at it again, with an installation of 13 wind turbines that Jacobs quickly topped with a four-escalator installation by French conceptual artist Daniel Buren, which created a graphic — and, dare we say, quite moving — fashion spectacle. (January, March, October)

POP INSPIRATION: Jean Paul Gaultier’s couture collection, inspired by the recently deceased Amy Winehouse, came down the runway too soon — January — for still-grieving fans and family. Gaultier continued to mine the pop music theme with his ready-to-wear show in October, an ode to 1980s juke box heroes complete with models decked out like Madonna, Grace Jones and other music stars. (January and October)

ENGLISH REMIX: For New York Fashion Week’s resident patrician, Ralph Lauren, "Downton Abbey"-as-inspiration was a natural. Not only was the designer’s fall 2012 collection inspired by the hit drama, but Lauren later signed on as national corporate sponsor for the long-running "Masterpiece" series. (February)

JUICY SEQUEL: Pamela Skaist-Levy and Gela Nash-Taylor, who brought the world the Juicy Couture velour tracksuit, debuted their new collection Skaist Taylor, which they described as "California eccentric," in a garage underneath Lincoln Center at New York Fashion Week. (February)

EYE CANDY: Celebrities are all-important for attracting attention nowadays. Say what you will about Kanye West and Kim Kardashian, and goodness knows we’ve all said something, but there’s no denying that the two are one of the world’s most fashion-conscious couples. Both have done design work or at least lent their names to fashion lines, and they made front-row appearances at runway shows throughout the year. West seems content to be sitting on the sidelines for now, having scaled back his ambitions to be a designer himself. (March, September)

LIFE AFTER CRUISE: Katie Holmes tried to move beyond her divorce from Tom Cruise by unveiling her Holmes & Yang collection at New York Fashion Week for the first time. Co-created with stylist Jeanne Yang, the collection was about elevating casual dress. (September)

VIRTUAL RUNWAY: Google co-founder Sergey Brin walked the runway with designer Diane von Furstenberg, using the platform to launch Glass by Google, a head-mounted, augmented reality technology. (September)

RUNWAY REVENGE: Liberty Ross walked tall on the runway at Alexander Wang’s high-profile New York Fashion Week show, proving to her wandering husband, director Rupert Sanders, actress Kristen Stewart (with whom he had his fling) and a universe of scandal-gawkers that there’s life after infidelity. The following month, the chastened Stewart attended the Balenciaga runway show in Paris as the new face of the house’s Florabotanica perfume. (September, October)

THE SLAP HEARD ‘ROUND THE WORLD: When New York fire marshals ordered the removal of 60 seats at the Zac Posen runway show, tensions were running high. So high, in fact, that while Lynn Tesoro, the co-founder of Posen’s PR firm HL Group, was trying to reorganize the seating arrangement, she was slapped by Jennifer Eymere, Jalouse magazine’s fashion editor. Tesoro has since filed a $1-million suit against Eymere, her sister and mother (who were allegedly also involved in the altercation). (September)

BATTLE FOR THE FUTURE OF FRENCH FASHION: This year’s October Paris Fashion Week saw ready-to-wear debuts at two storied French fashion houses, Raf Simons for Dior and Hedi Slimane for Yves Saint Laurent. The designers’ approaches couldn’t have been more different. Simons rewrote the codes of French design for a new generation with a collection that was all about color, movement, lightness and legs. Slimane paid homage to Saint Laurent’s rich hippie look with a collection that was more like a greatest hits album than a revolutionary new sound. (October)

NEVER-ENDING RUNWAY: A new Guinness World Record was set in Hong Kong for the longest runway: two miles. The show, a collaboration between the Danish Fashion Institute and the Hong Kong Designer’s Association, featured 346 models who had to walk 45 minutes to complete the trek down the pink catwalk next to Victoria Harbour. (December)