Taylor Swift attended the London premiere of Renaissance: A Film By Beyoncé yesterday, returning the favor after Bey made a special appearance at the Los Angeles premiere of Taylor Swift: The Eras Tour back in October. Swift arrived in a theme-appropriate silver gown, and stopped to take photos with the fans gathered outside. Beyonce's concert doc, which is expected to open between $30-$40 million this weekend, already held its star-studded U.S. premiere in Los Angeles last Saturday. Swift's Eras Tour and Beyoncé’s Renaissance tour were the most-talked-about events of the summer, and the friendship between the two singers dates back to the 2009 VMAs. Swift even called her "a guiding light throughout my career" in an Instagram post after Bey attended the Eras Tour movie premiere.