'Law & Order: SVU': This Was The Season 1 Cast

Law & Order launched its very first spin-off, Special Victims Unit, all the way back in 1999. Today, Law & Order: SVU is currently in its 22nd season! This gallery takes a look back at season 1 of the popular and long-running NBC series. Look for some familiar faces and facts you may not have known about the show!

Today, Christopher Meloni and Mariska Hargitay are two of the Law & Order universe's most popular figures. But back in 1999, the stars made their debuts in season 1 of Law & Order: SVU. In this photo, "Det. Elliot Stabler" and "Det. Olivia Benson" are seen at NBC's 1999 summer press tour, a few months before SVU premiered its very first episode!

"Det. John Munch" was another main cast member in Law & Order: SVU season 1. But, for many NBC viewers, this wasn't the first time they'd seen Richard Belzer's character. He actually portrayed "Munch" on NBC's Homicide: Life on the Street for six seasons prior to joining the new SVU spin-off in 1999. He'd go on to be a regular until the end of the show's 15th season. Belzer is pictured here in a '90s promo for Homicide.

This SVU season 1 promo photo shows one short-lived cast member and another series veteran. On the left is actor Dean Winters, who played "Brian Cassidy" - the partner of Belzer's "Det. Munch." Winters only appeared in the first half of season 1 before exiting for commitments with the show Oz. On the other hand, Dann Florek, a Law & Order star, brought his role of "Capt. Donald Cragen" over to SVU for its debut season. He remained with the series until season 15.

Following the departure of actor Dean Winters and his "Det. Brian Cassidy," actress Michelle Hurd joined the main cast of SVU season 1. She portrayed "Det. Monique Jeffries" for the last half of the premiere season and in season 2 as the partner of "Det. Munch." She departed in season 2 after Hurd and the producers were unable to agree on how to develop her character.

Mariska Hargitay's "Det. Olivia Benson" has come a long way since SVU season 1! In fact, she's the lone cast member who's remained with the show for all 21 seasons. She's also now risen to the unit's captain. Hargitay was 35 years old when season 1 aired and, today, is now the face of SVU.

"Det. Elliot Stabler," the partner of Hargitay's "Det. Benson," also enjoyed a long run of his own after debuting in SVU season 1. Actor Christopher Meloni, who was 38 years old in season 1, stayed with the show for 12 seasons. In this photo, Meloni is seen attending an event in 2000. He's also set to reprise his role as "Stabler" for the first time in almost a decade come SVU season 22 along with a new spin-off series for his character.

Nearly all of Law & Order's main cast made appearances in SVU season 1. But, of the guest stars, ADA "Abbie Carmichael" led the way with six appearances that season. Actress Angie Harmon, however, didn't appear in any further SVU seasons, and left Law & Order a few years later after season 11. RELATED: Law & Order - Where Is "Abbie Carmichael" Now?

Actress Reiko Aylesworth was another ADA with a short-lived entry in the Law & Order universe. Though she did appear in three episodes of SVU's first season, her ADA "Erica Alden" wasn't seen beyond this minor role.

Here's a great shot of "Stabler" and "Benson" on set filming Law & Order: SVU season 1! We're looking forward to their reunion in season 22...