In court Wednesday, Britney Spears was represented for the first time in her 13-year conservatorship by a lawyer she herself had chosen: Mathew Rosengart. Rosengart comes to the Spears conservatorship with a lot of star power. He was recently highlighted in the 2021 edition of Variety's annual "Legal Impact Report," which mentions that he represents Steven Spielberg and his Amblin Entertainment, actors Julia Louis-Dreyfus and Keanu Reeves, actor Sean Penn and his non-profit aid group CORE, musician Eddie Vedder and the talent and sports agency Creative Artists Agency. Other clients include Shark Tank's Daymond John, actor Winona Ryder and Miami Heat basketball player Jimmy Butler. He has also been named repeatedly to The Hollywood Reporter's annual "power lawyer" list, including in 2021.Before turning his attention to the entertainment industry, Rosengart served as a federal prosecutor, and worked at the Justice Department as an assistant U.S. attorney. According to a recent New York Times profile, he also clerked for David Souter, when the former Supreme Court justice was a state judge in New Hampshire.In court Wednesday, Rosengart asserted that it was probably never appropriate to have instituted a conservatorship over Spears in the first place. He also had words aimed at the pop star's father, Jamie Spears, who has had primarily control over the conservatorship for the past 13 years: "If he loves his daughter, it's time to step aside so Ms. Spears can move forward to a healthy, productive life." Copyright 2021 NPR. To see more, visit https://www.npr.org.