With just two weeks left before The Crown returns to our screens for Season 5, now’s the perfect time to go back to the beginning. And what better way to look back than revisiting some of Season 1’s most intricate costumes?

In the behind-the-scenes video above, Season 1 costume designer Michele Clapton shares the secrets behind some of The Crown’s most iconic sartorial creations, from then-Princess Elizabeth’s (Claire Foy) wedding gown in the series premiere, to Princess Margaret’s (Vanessa Kirby) eye-catching styles.

Clapton and her team created around 350 costumes for the main cast over the course of the season, on top of dressing nearly 7,000 extras — each of whom had between two and five costumes of their own. What’s more, they went to painstaking lengths to recreate the fashion of the era, which spans the late 1940s into the mid-1950s. To perfect Elizabeth’s 1947 wedding gown, for example, Clapton had teams of six people working in shifts for six weeks to embroider the dress and train. Foy was awed by the level of detail that went into her costumes. “A lot of the dresses that I wear are replicas of things that she wore,” she says in the video.

“We do it as properly as we can,” Clapton adds. “If we didn’t do it that well, we couldn’t tell our other stories.”

The costumes — whether Philip’s (Matt Smith) military uniforms or the queen mother’s (Victoria Hamilton) hats — had to be both period-accurate and reflective of each character’s look. They  also had to serve the larger narrative. Clapton gives the example of the contrast between Elizabeth and Margaret’s styles as an example of the tension that sometimes exists between the royal sisters. While Elizabeth has to assume the heavy burden of the crown, Margaret is much more fun-loving and free with the clothes she wears. “Margaret was the biggest fashion icon of the ’50s and ’60s,” Kirby says. “She designed her own things and she looked amazing. She really led waves of fashion.”

As for Smith, he simply relished the opportunity to step into Philip’s shoes — literally.  “I think the fashion of that time is really cool,” he says. “The suits I get to wear are beautifully cut, all the military stuff looks really great. And the girls, I think in particular, look really brilliant.”