Chancellor Gordon Brown joined senior executives from across the national press at St Bride's Church, Fleet Street, to gave thanks for 100 years of the Newspaper Publishers Association.
The NPA was formed by press owners Northcliffe and Pearson to enable them to better negotiate with the print unions.
And News International chief executive Les Hinton spoke of an 80-year struggle with the unions, which he said culminated 20 years ago when Rupert Murdoch moved his titles to Wapping.
Telegraph Group chief executive Murdoch MacLennan spoke about the future of newspapers in the week that his company completed its move from Canary Wharf to a new high-tech multimedia newsroom in Victoria, London.
He said that the century of newspaper heritage was "something sacred and held in trust for those who follow".
He added: "That task is more difficult now than it has ever been before, because we are in the midst of one of the most vibrant and dynamic developments in our history.
"Not since Wynkyn de Worde was fashioning the printing press very close by here have we been gripped by such massive change." MacLennan said: "Readers increasingly want to receive and read their content in different ways. Whereas once our competitors were national, now they are international."
Lord Rothermere, proprietor of Daily Mail and General Trust, read an extract from This Is Fleet Street, a 1966 book by Vivian Brodsky, which extolled the glories of old Fleet Street.
No national newspapers are now left in Fleet Street, but the assorted editors, owners and other executives repaired to the old Express Newspapers building — now home to investment bank Goldman Sachs — for refreshments after the service.