Not long ago, Toronto’s Globe and Mail newspaper commissioned eight graphic designers to create new logos for Toronto. The most popular design, as determined by readers’ votes, was a logo that showcased a prominent letter “T” made up of a hundred and forty small circles, which signified the city’s hundred and forty neighborhoods. Other logos had emphasized the city’s multiculturalism. One featured several cranes, in a nod to Toronto’s status as a high-rise construction capital. Perhaps the most vivid offering, though, displayed a circus tent adjacent to the text “Toronto: A Ford Brothers Production,” alluding to the recent headline-dominating antics of Mayor Rob Ford. “What no Gravy Train?” one person tweeted, in reference to Ford’s oft-repeated term for wasteful government spending. On Facebook, one comment read, “Should have made a crack pipe with directions to the hood.”

The Globe’s logo project wasn’t fashioned as a direct response to the months of negative media attention heaped upon Toronto’s mayor—who, on occasion, has found himself explaining his actions (smoking crack cocaine, among others) when standing between a podium and a backdrop that bear the city’s current insignia, a version of its modernist City Hall. But the newspaper acknowledged that the project came at an opportune time.

It’s not immediately obvious that changing a logo would change the city’s reputation, any more than changing a refrigerator’s light bulb changes its ability to keep food cold. And yet, cities persist at changing them. Jonathon Day, a professor of hospitality and tourism management at Purdue University, told me that this is understandable. “When the locals say, ‘We need a new brand,’ part of what they’re saying is that the way they’re being portrayed is not the way they see themselves,” he said. There’s a kind of cognitive dissonance to Ford’s association with Toronto, long seen as a stylish, cosmopolitan city—sort of like seeing a Tiffany & Co. next to a saloon with boarded-up windows.

City emblems can be traced to twelfth-century Europe, D’Arcy Boulton, a professor of medieval studies at the University of Notre Dame, told me. This period saw the development of heraldry, a profession that oversees the creation and regulation of coats of arms, which were displayed on the flags and shields of nobles to distinguish themselves from their opponents during chivalric competitions and on the battlefield. Much as an N.B.A. player wears a jersey on the basketball court, the practice was one part pragmatism, one part pageantry. Over the next hundred years or so, guilds, churches, and towns, which had been using monochromatic seals as their mark of authority, began adopting their own coats of arms. Think of London’s white shield with a red cross flanked by two dragons. The emblems sometimes meant different things to different people. Still, coats of arms were a useful way of identifying various groups at a time when the peasantry was largely illiterate, relying on the Church’s stained-glass images to teach them theology.

In recent decades, heraldry has been losing ground to modern graphics, as cities borrow from the logos of the corporate world. While many cities still have a coat of arms—Toronto’s, for example, displays a blue “T” on a yellow shield held upright by a beaver and bear—councils have largely let them fall by the wayside, especially as more cities have turned to a relatively new trend called destination branding, which aims to package cities, regions, and countries as marketable products to lure potential tourists and investors.

“Heraldists like myself have a deep dislike of institutions that abandon their coat of arms in favor of a logo,” Boulton said, about the recent shift. “While we don’t mind logos, we tend to feel that the traditional forms are more dignified and have a certain character that would be sad to lose. There is also a beauty in the design of arms, partially because of the rules that constrain the combinations of colors, figures, and spacing to make the design as clear and recognizable as possible, even from a distance.”

Perhaps the most famous modern city logo is the iconic “I ♥ NY” emblem, created in 1977 by the graphic designer Milton Glaser on behalf of New York State. With New York City having nearly filed for bankruptcy two years earlier, the logo was part of a strategy to revive both the state and the city’s image and, in turn, their economies, according to Miriam Greenberg, an associate professor of sociology at the University of California at Santa Cruz and the author of “Branding New York: How a City in Crisis Was Sold to the World.” The juxtaposition of stark letters with a soft heart captured both the toughness and vulnerability people loved about New York City, she said—and their deep affection for a place on the verge of collapse.

“It is possible for an artist or designer to tap into the zeitgeist and create an image that resonates at a particular moment,” Greenberg said, “but they have to be knowledgeable about what the underlying fears and issues are.” A new logo probably won’t transform a city, in other words, unless it’s part of a package of initiatives to address a city’s challenges.

Amsterdam, too, has a much-praised logo. Its “I amsterdam” campaign and matching giant letters found at various points in the city—with “I am” in red and “sterdam” in white—has come to symbolize the city’s inclusiveness. One promotional video shows a rotating cast of diverse people accompanied by the captions “I am passionate,” “I am curious,” “I am inspired,” and so on. In an academic article, Mihalis Kavaratzis and G. J. Ashworth suggested that the impetus behind the “I amsterdam” launch in 2004 was a desire to re-highlight positive aspects of the city, as a counterpoint to Amsterdam’s international reputation of having a liberal attitude toward drugs and prostitution.

New logos don’t always work out so well. During the eighties and nineties, Seattle successfully branded itself as “The Emerald City,” which was the winning epithet in a public competition. In 2001, however, the city decided to upgrade. It created a new logo: a rebus that featured an eyeball, the “@” symbol, and the letter “L” (pronounced “See-at-L”), above the slogan, “Seattle: soak it up!” Years later, a former C.E.O. of Seattle’s Convention and Visitors Bureau, Don Welsh, admitted that one of the logo’s several problems, beyond simply not resonating with people, was that it never told anyone anything unique about the city.

In 2006, the city unveiled a new tagline: “Metronatural.” Meant to encapsulate Seattle’s wealth of both urban and outdoor life, the branding effort also met its critics. “It sucks. Lose it. The quicker the better,” wrote Timothy Egan, a Seattle native and columnist at the Times. “Sounds more like a manicured, effete fellow wearing a hemp shirt—or perhaps some kind of automotive laxative,” said another dissenter. Tom Norwalk, the current C.E.O. of Seattle’s official destination-marketing organization (a revised version of the city’s Convention and Visitors Bureau), understands that the brand may have confused people more than it informed them. “We got into trouble because I think it has a totally different meaning in Germany,” he said. “A ‘nudist colony,’ I think, is how the translation came out in one newspaper. So that faded away slowly.”