Celtic cross memorial, Deansgrange Cemetery, Dublin. Courtesy of Andy McDonnell. By Sam McGrath An impressive Celtic cross is the focal point of the Republican Plot in Deansgrange Cemetery, South Dublin. Unveiled in August 1929, it commemorates three Irish Republican Army (IRA) members who died in London in the years 1921-22. Reginald Dunn and Joseph O’Sullivan were hanged for the assassination of Field Marshall Sir Henry Wilson outside his home in central London in June 1922.