Greeted with hostility and derided as a Modernist affront when it was first proposed as the main entrance to Paris’ Musée du Louvre, this 71-foot-high glass and stainless steel pyramid designed by I.M. Pei, FAIA, now rivals the Eiffel Tower as one of France’s most recognizable architectural icons.

Born of President François Mitterrand’s quest to modernize the Louvre in the early 1980s, Pei’s pyramid is the form that thrust the 800-year-old Palais complex into the modern era. As one juror noted, it “established a benchmark for new, modern architecture that enriches an historic setting with integrity and respect for both history and progress.”

In the 1970s, the Louvre’s courtyard was packed cheek to jowl with cars while the museum’s several million annual visitors endured agonizingly long waits only to face a disorienting slog through a maze of corridors on their way to the view the collection.

When he was selected as the architect, Pei faced a seemingly insurmountable challenge: reorganizing and expanding the museum without compromising the historic integrity of one of France’s cherished monuments. To execute the project, Pei wove together an unprecedented amount of cultural sensitivity, political acumen, innovation, and preservation skill. As one juror noted, the project has become “an internationally renowned symbol for Paris and an example of the prowess and legacy of I.M. Pei.”

The entirety of the project, known as the Grand Louvre, was executed in two phases over the course of a decade. For the first phase, which gave rise to the pyramid, Pei reorganized the museum around the central courtyard, the Cour Napoléon, transforming it from a parking lot to one of the world’s great public spaces. Long-shuttered passageways through the palace were reopened, reinvigorating the plaza and vaulting it into a position of vital gathering space and a bridge to the city beyond.

“The test of great architecture is being responsive to the site, defining a place that is transformative,” noted one juror. “Pei’s addition contributes to the experience of the Louvre creating a place that enhances the lives of all who visit the Louvre, and those who never go inside as well.”

Additional support space that would preserve and showcase the character of the palace was a primary goal for the project. Heading underground, Pei added 670,000 square feet below the Cour Napoléon, with an elegant lobby area providing direct access to all three wings of the museum. Natural light, which floods the space through the pyramid and three smaller iterations that surround it, is critical to the project’s legacy and echoes the illumination to be found within the collection. As a corollary benefit of the expansion, the construction process unearthed a trove of medieval artifacts, original foundations, and walls, many of which are exhibited within.

Twenty-seven years since the project was completed, Pei’s success has been reaffirmed in the museum’s visitorship, which has more than tripled since the expansion. To accommodate the influx, the museum undertook its first renovation of the reception area directly beneath the pyramid recently and took distinct measures to maintain the integrity of Pei’s design.

Despite the rancor that surrounded the design’s unveiling, Pei gave France an unexpected treasure that its citizens and visitors from around the globe value as much as the priceless works of art contained within the Louvre. Bringing “life, action, and beauty to what was already beautiful,” as one juror noted, the project fused modernity with a swell in national pride for a historic building.

“When you ask the visitors, ‘Why are you coming to the Louvre?’ they give three answers,” said Henri Loyette, President-Director of the Louvre from 2001 to 2013. “For the Mona Lisa, for the Venus de Milo, and for the pyramid.”