Of that extraordinary era, only this brief clip remains.
Soon after he had completed his doctoral dissertation on cubism at the Courtauld Institute of Art, London, it was published as Cubism, A History and an Analysis, 1907-1914 (1959), and has stood ever since as the clearest exposition of that extraordinary era in the history of the art of the 20th century.
The 1978 cut in the capital gains tax from a maximum of nearly 50% to 28% turbocharged the extraordinary era we now label as high tech in the information age.
But, ultimately, patients are the ones who benefit most from the extraordinary era of research that we are now presented with.
Is this the official beginning of the end of an extraordinary era of power in Cuba?
Two years later, the studio was converted into a small house museum, and although Sembrich and her acolytes are long gone, this trove of operatic memorabilia offers a haunting picture of an extraordinary era.
And the world will know more about an extraordinary era in history, when two great religions were born.
As Lyn Gardner noted in her review of Tunnel 228, "We are living through an extraordinary era in British theatre.
After an extraordinary era of construction and renovation, demolition and replacement, there will almost certainly come a long period in which little to nothing gets built.
The videos, with a million or so YouTube views, findable by Googling Roll Deep Conflict, are a window on to an extraordinary era in British musical history.
