He is one of seven high-profile claimants, including Sir Elton John, accusing Associated Newspapers of various unlawful behaviours, such as phone bugging and illicitly obtaining personal health records.
The High Court in London will hear evidence over nine weeks, with Prince Harry scheduled to appear next Thursday, marking his second court appearance in three years.
Associated Newspapers vehemently denies the allegations, dismissing them as 'preposterous smears' and part of a wider conspiracy.
The case carries high stakes, with reputations and millions in legal costs on the line, and could be a significant moment in the ongoing challenge to British media practices.