Chigi was born in Ariccia, the son of Imperial Prince Mario Chigi Albani della Rovere, VII principe di Farnese [it] and Princess Antoinette zu Sayn-Wittgenstein-Sayn.[1] The House of Chigi, his father's family, was among the oldest and most prominent noble families of Rome, to which had belonged Pope Alexander VII (1599–1667), who conferred upon his nephew Agostino Chigi (1634–1705) the hereditary princedoms of Farnese (1658) and Campagnano (1661), as well as the dukedoms of Arricia and Formello (1662), also procuring for all descendants of the Chigi male line the title of Imperial prince and princess from the Holy Roman Emperor Leopold I in 1659.[1] In 1509 Pope Julius II had authorised the Chigi family to augment their name and arms with his own, della Rovere, and would become Ludovico's ancestor (in the 13th degree) through six lines of descent from that pope's illegitimate daughter, Felice della Rovere.[1]
On 4 November 1914, Chigi's father died and he succeeded as 8th Prince di Farnese and di Campagnano, 4th Prince di Soriano, 8th Duke di Ariccia and di Formello, Marchese di Magliano Pecorareccio, Hereditary Marshall of the Holy Roman Church and Guardian of the Conclave.[1] Chigi was responsible for three papal conclaves.[2] He was an honorary member of the Pontifical Academy of Sciences.[2]
On 30 May 1931, Chigi was elected Grand Master of the Sovereign Military Order of Malta,[3] Both of Chigi's parents had been members of the Order: his father was a Bailiff Knight Grand Cross of Devotion (since 21 June 1879)[4] and his mother was a Dame decorated with the Cross of Devotion (since 10 June 1876).[5]
Under Chigi's leadership the order engaged in large-scale hospitaller and charitable activities during World War II. In 1947, he was appointed president of an international committee to oversee the rebuilding of the Abbey of Monte Cassino.[6]
Chigi died in Rome of a heart attack at the age of 85.[2]
After Chigi's death, the Order spiralled into difficulties and Pope Pius XII forbade the immediate election of a new Grand Master which would have been usual. The Order was governed by a Lieutenant appointed by Rome (first Antonio Hercolani Fava Simonetti and then Ernesto Paternò Castello di Carcaci) and a Commission of Cardinals until the Constitutional Charter was approved by Apostolic Letter of Pope John XXIII in 1961 and Angelo de Mojana di Cologna was elected as new Grand Master. Cardinal Nicola Canali had attempted to become Grand Master after the death of Chigi in 1951 and a great controversy erupted about the status of the order as a religious and sovereign one. In addition to this, there was the controversy of Yves Marsaudon (a Freemason in Paris who had become a prominent member of the Order of Malta during the time of Chigi as Plenipotentiary to France and promoted ecumenism).
