Monaco's Royal Twins Steal the Spotlight (and the Balcony!) on National Day: See All the Best Moments

Monaco’s Prince Albert, Princess Charlene and their royal twins gathered together on the palace balcony alongside the rest of the royal family on Tuesday to celebrate Monaco’s National Day.

In addition to the pomp and circumstance and a colorful parade, there’s also a severe space crunch, according to the principality’s ruler. The number of marriages and births which have swelled the Grimaldi family ranks in just the past few years have created something of a royal traffic jam on the balcony.

Last year, Monaco’s Princess Caroline came to a crowded window holding two newborn grandchildren — with a third being held beside her and another grandson perched on the balustrade. Behind her, other family members had to wait their turn.

“We’re running out of space for everyone,” Prince Albert II tells PEOPLE. “We’re going to have to create new windows, build new balconies.” Turning half-serious, he adds, “It is actually an issue. Before we used to have family and high-ranking staff from the palace, people who worked with us very closely from the household stand in the windows.

“There’s no room. All the other senior palace officers are in another location now at the foot of the palace entrance,” he adds, noting his growing family has celebrated two weddings — niece Charlotte and nephew Louis — and three christenings since last year’s National Day event.

Prince Albert jokes, “I don’t think I can face up to another christening or wedding right now,” before adding, “Actually, it’s great feeling to have that many new members of the family and everybody seems to get along well.”

Introduced in 1857 by Prince Charles III, National Day is the one date of the year that sees the entire assembled royal family traditionally greet their citizens. Historically, it has shifted throughout the calendar, being held on each subsequent reigning prince’s patron saint’s day. Upon his 2005 ascendance, however, Albert retained the Nov. 19 date in honor of Prince Rainier III, his father.

There was another new tradition added this year. Albert’s 4-year-old son, Prince Jacques, appeared before gathered crowds wearing his first-ever uniform.

“Yes, he’s being outfitted this year. I think they still have one fitting to do but he’ll be in a uniform. And that’ll be great fun,” Albert previously told PEOPLE.

Prince Jacques looked sharp in his uniform, and even appeared at the window wearing a red, white and blue helmet to complete the look.

Jacques’ twin sister, Princess Gabriella “has outgrown her little Monegasque outfit, and I’m not certain whether the new one will be ready in time — but she’ll be very elegant though,” Albert added.

The little princess appeared wearing a red ensemble topped by a blue coat, complete with a red beret and purse. Perhaps she was channeling her mother, Princess Charlene, who dressed in all white for the event, including a stylish fedora.

Prince Albert shares that Gabriella can be camera shy.

“It’s funny,” her father says. “There are some moments now where she adores the camera and some moments where she shies away completely, where she says, ‘No, no more photos.’ And she kinds of turns away or turns a grumpy face. You kind of have to catch her in a good mood.”

The National Day program contained two specific tributes this year, including one celebrating the historic centennial relationship between Monaco and the U.S. Military. The USAF Drill Team has been invited to march in front of the palace.

“There’s a link to 1919, when a detachment of soldiers came to Monaco to thank it for treating wounded here during the last two years of the conflict,” Prince Albert explains.

The event will also honor the late Princess Grace.

“We’re going to have a small tribute to mom because [Nov. 12 marked] the 90th year anniversary of her birth,” says Albert. The planned tribute will culminate a great number of organized events and exhibitions across the world over the past year celebrating American actress turned princess. “You know, it’s amazing how much people care,” the prince reflects.

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“There were different initiatives by the people who wanted to pay tribute to her. And mostly by people that she’d never met,” he says. “It’s unbelievable that she’s still so present in everyone’s minds and everyone’s hearts that they feel the urge to commemorate here and to pay tribute to her in such touching ways. It’s extremely heartwarming not just for me but for our entire family, too.”