Fifteen years ago, Charleston’s favorite improv comedy team — The Have Nots! — were born in a bloodless birth at Piccolo Spoleto. They didn’t perform as an official part of the festival. Instead, Brandy Sullivan, Greg Tavares, and three other scrappy kids took over a bar and played on the fringes, hoping to attract just a small portion of festival-goers. Whether any Spoletians found them or not is pretty much irrelevant today. The locals did, and, as the years went by and The Have Nots! winnowed down to three, they became part of the scene, and Charleston audiences discovered a real penchant for improv comedy.

Today, “fringe” is an official and impressive part of the official Piccolo Spoleto. It took them a while to get the official nod, but once they did, Sullivan and Tavares didn’t mess around. It’s grown to include not only The Have Nots!, but 35 players from Theatre 99, the company The Have Nots established in 2000, who will put on 28 shows. Then there are the 30 visiting performers who will put on nearly 50 shows over the course of the 17 days of Spoleto.

They’ve come a long way baby. Last week, Sullivan and Tavares were making final preparations for their biggest and busiest weeks of the year. The freshly painted set backdrop had just been installed — each year graphic designer Gil Shuler creates a new look for the stage — and the two were busy fielding calls and scheduling rehearsals.

“The set is the first sign,” says Sullivan about the looming festival. And the milestone they’re hitting this year is a big deal for them personally, regardless of whether they capitalize on it as a marketing ploy. Over the last 15 years, the two — virtual siblings — have built a veritable comedy empire.

In addition to Piccolo, they co-produce (with the Charleston City Paper) the annual Charleston Comedy Festival. They also perform every week at Theatre 99 and teach workshops to comedy-loving locals throughout the year. Some of those students have stayed with it, becoming full-fledged company members, and others have moved to Chicago to see if they can translate what they’ve learned here into a spot on the famed Second City or iO stages.

A handful of performers have created what the two call “name shows” and many of those will be performed this weekend.

One of the longest-running is Mary Kay Has a Posse, an all-female show that uses the premise of a talk show to get things going. Sullivan stars in Mary Kay along with Jennifer Dyer-Buddin, Camille Lowman, and Jessica Chase, who reunite a few times a year because only two of the women live here in town. “It’s like a long distance relationship,” says Sullivan. “And each show is a reunion show.” They’ll perform five times during the festival.

“Someone’s gonna cry,” jokes Tavares, who has his own name shows. On opening weekend, he’ll perform with Sullivan in The Have Nots! Comedy Improv Jam, which will include visiting performers in addition to Sullivan, Tavares, and fellow Have Not! Timmy Finch. “We guest a lot of people in,” says Tavares. “We’re liable to pull a guy in from Upright Citizens Brigade, FrankenMatt, or The Reckoning. Every night has a vibe of the finale.”

Tavares has written and performs in another wildly popular show — The History of Charleston for Morons, which he says is “a show for everybody, especially old people.” There’s a reason it’s a matinee.

Another hot ticket is Big Dicktionary, which stars Timmy Finch and John Brennan riffing on one word and breaking all the rules, for a 50-minute romp.

Brennan has become very familiar to audiences, performing his one-man show Banana Monologues — think Vagina Monologues without the hootie — throughout the year. He’ll be taking his show to New York in June to showcase for some interested directors. He’s hoping it will translate into something big. “It’s awesome. I got a shot at the dance,” he jokes.

For Sullivan and Tavares, Piccolo is their big dance. Each year, it requires them to host visiting performers, run Theatre 99, oversee performances in three venues, perform in their own shows, and manage to sleep, eat, and see their loved ones along the way. Most amazing is their ability to make audiences laugh through it all.