Miley Cyrus has penned a lengthy letter to Hannah Montana to mark the 15-year anniversary of the show’s first episode – you can read it below.The teen sitcom premiered on the Disney Channel on March 24, 2006, when Cyrus was just 13 years old. It concluded back in 2011 after four seasons and a feature-length film (released in 2009).Taking to Instagram, the pop star reflected on the series in a heartfelt handwritten note.