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Pierre Nkurunziza is considered the longest-ruling president in Burundian history. He first became president in 2005 and was re-elected in 2010 and 2015. His third term in office was controversial, as it was ruled unconstitutional by the Constitutional Court. Nkurunziza defied the court's ruling and remained in office, leading to widespread protests and violence. He was eventually re-elected in 2020, but died in office in 2021.