OXFORD librarian John Simmons did not forget his old college in his will. But he has certainly set All Souls a monumental challenge before it can hope to receive a share of his £888,000 estate.

Prof Simmons had always maintained that the college had made a terrible mistake moving its famous sundial designed by Christopher Wren from the college chapel wall.

Now under the terms of his will, All Souls must move the sundial to its original place if it is to receive any of his money.

Prof Simmons, who died last year aged 90, was a leading Slavonic scholar, who spent much of his career in Oxford libraries in charge of Slavonic books.

He was also an expert on sundials and shared a 130-year grievance with other Oxford traditionalists about the huge and elaborate sundial, designed by Britain's greatest architect in 1658.

Recognised as one of the most beautiful in the world, the sundial was moved from the southern chapel wall in the front quadrangle to the 200ft Codrington Library in the 1870s.

The relocation had two unfortunate consequences. The first is that Wren's dial, once so accurate that the Oxford watchmakers set their watches by it, no longer told the true time. More grievous still, members of the college complained that the sundial upset the consummate symmetry of the North Quadrangle.

Prof Simmons's will says that part of his estate, a sum not yet specified, will go to the college on condition that the Wren sundial is removed from the Library and "re-erected where it was originally positioned by Sir Christopher Wren, that is to say over the south front of the college Chapel."

And there is a further condition too, with the will laying down that that the gravelled areas in the college's north quad must be paved, or covered in flagstones.

Prof Simmons, of Upland Park Road, served at various times as a librarian archivist, lecturer and Senior Research Fellow at All Souls.

He also also leaves a share of his estate to the Bodleian Library, on condition that three funds "for specific purposes" are created. The Oxford colleges St Antony's and The Queen's College and the Taylor Institution are all left £10,000 each.

One of his proudest achievements had been in building up collections of Russian books in the Bodleian and Taylorian libraries.

A world authority on the study of paper, in later years he published on the history of All Souls and its buildings. His wife predeceased him in 1999.

A spokesman for All Souls said: "The college has not yet seen the will, I believe."