By Niamh Spence Prince Harry may finally be forced to renounce his royal titles if he takes up US citizenship, according to an expert. Harry and wife Meghan Markle became the Duke and Duchess of Sussex by order of the late Queen Elizabeth when they got married in 2018. But they have faced calls to give up the honour ever since they famously stepped away from royal duties in 2020 and delivered a series of blistering attacks on the family in a series of interviews, podcasts and Harry’s autobiography, Spare. READ MORE: Meghan and Harry’s children get new surname as couple abandon 64-year royal tr…