When, in 1975, two of the authors (D.K. and H.S.) proposed to change their field of research back to the subject of exact solutions of Einstein's field equations, they of course felt it necessary to make a careful study of the papers published in the meantime, so as to avoid duplication of known results. A fairly comprehensive review or book on the exact solutions would have been a great help, but no such book was available. This prompted them to ask ‘Why not use the preparatory work we have to do in any case to write such a book?’ After some discussion, they agreed to go ahead with this idea, and then they looked for coauthors. They succeeded in finding two.

The first was E.H., a member of the Jena relativity group, who had been engaged before in exact solutions and was also inclined to return to them. The second, M.M., became involved by responding to the existing authors' appeal for information and then (during a visit by H.S. to London) agreeing to look over the English text. Eventually he agreed to write some parts of the book.

The quartet's original optimism somewhat diminished when references to over 2000 papers had been collected and the magnitude of the task became all too clear.