He probably left Carrara soon afterwards, returning to Rome by way of Florence.

The only authoritative account of the original project of the Tomb is that of Condivi; Vasari's account was not published until his second edition in 1558.

The architectural drawings, said to be designs for this Tomb, are of doubtful authenticity; most of them are certainly not by Michael Angelo.

We must therefore study Condivi, who probably got the details from Michael Angelo himself, though he, too, must have had great difficulty in recalling the ideas of forty-eight years ago.( 85) The plans for the new church of St.
Peter's, the largest church in Christendom, were altered to embrace this huge monument, but a transept of the little church of San Pietro in Vincoli gave ample space for the final scheme, when it was set up in 1545.
The only statues we know belonging to it by Michael Angelo are the Moses and the two bound Slaves in the Louvre; the other six statues in San Pietro in Vincoli were finished by assistants.

The unfinished marble figures so unworthily housed in the stupid rock-work grotto of the Boboli Gardens, Florence, may have been for the Tomb, although their measurements do not agree with the Slaves of the Louvre.