The day after the death of Michelangelo on February 19, 1564, the notary promptly sent by Pope Pius IV to the Roman workshop of the artist, compiled an inventory of all its assets. Among the works mentioned is a sculptural group "another statue at the front of which is a Christ with another figure above, stuck together, hewn and unfinished", today identified with the Rondanini Pietà.
Unfortunately, following the compiling of that inventory, all reference to the work was lost, with the exception of a rumour in 1652 that the sculpture may have been in Rome.

The Pietà resurfaces

Only on 13th August 1807 does credible information on the whereabouts of the Pietà re-emerge, when it was certified as being in the possession of the Marquis Giuseppe Rondinini (name later changed to Rondanini), a collector of paintings and over two hundred sculptures, many of which are marked, as was the Pieta, with the letters M.G.R. N.I

The inventory drawn up by the assessor and sculptor Carlo Albacini a few years after the death of Rondanini mentions the Pietà, but denies the authorship of Michelangelo. Albacini, in fact, considered it to be a modern sculpture, thus lowering its value. It is due to this misconception that in the 19th century the Pietà followed the fate of the Palazzo Rondanini, which also failed to garner any interest among art historians and collectors. Even the discovery made by the director of London’s South Kensington Museum, John Charles Robinson, in 1857 linking the Rondanini Pietà with sketches for a Pietà that were uncovered in the Ashmolean Museum in Oxford were ignored.

The sale of the Pietà

In 1904, the then owner of the Palazzo Rondanini, Prince Odescalchi, sold the building to Count Roberto Sanseverino Vimercati complete with its furniture, which included the Pieta. The Italian state, which at that time thanks to the law of 1902 could have claimed the right of first refusal on the work, did not think it appropriate to purchase. It was only from 1909 that interest in the sculptural group was awakened with new interpretations and studies on Michelangelo. In 1949 following a legal battle between heirs, the Pieta was put on sale. It was purchased in 1952 by the City of Milan, which moved it to the Civic Art Collections of the Sforza Castle.
On 2 May 2015, the Rondanini Pieta was given a new home within a dedicated area of the Sforza Castle, that of the Old Spanish Hospital, now the new Museo Pietà Rondanini.