Question: Who is the father of the maker of the Memorial to Ippolito Merenda?

full_context: Document 1: Bust of Francesco Barberini: The Bust of Francesco Barberini is a marble sculpture by the Italian artist Gian Lorenzo Bernini, now in the National Gallery of Art in Washington, D.C.. It was executed in 1623. It was commissioned by Pope Urban VIII, who was nephew of Francesco Barberini, an apostolic protonotary. Francesco had actually died in 1600 so Bernini created the bust from an existing painted portrait. The painted portrait is in Corsini Collection in Florence; Bernini made close use of the design, although the painting was a three quarter portrait as opposed to a bust of head, shoulders and upper body.
Document 2: Memorial to Ippolito Merenda: The Memorial to Ippolito Merenda is a funerary monument designed by the Italian artist Gian Lorenzo Bernini between 1636 and 1638. Along with the similar monument for Alessandro Valtrini, this artwork was a startling new approach to funerary monuments, incorporating dynamic, flowing inscriptions being dragged by a moving figure of death. It is in the church of San Giacomo alla Lungara in Rome.
Document 3: Bust of Gabriele Fonseca: The Bust of Gabriele Fonseca is a sculptural portrait by the Italian artist Gian Lorenzo Bernini. Executed sometime between 1668 and 1674, the work is located in San Lorenzo in Lucina in Rome, Italy. Gabriele Fonseca was the doctor to Pope Innocent X.
Document 4: Memorial to Maria Raggi: Memorial to Maria Raggi is a sculptural monument designed and executed by the Italian artist Gian Lorenzo Bernini, in 1647. The monument is attached to a pillar in a nave of the church of Santa Maria sopra Minerva in Rome.
Document 5: Charity with Four Children: Charity with Four Children is a sculpture by the Italian artist Gian Lorenzo Bernini. Executed between 1627 and 1628, the work is housed in the Vatican Museums in Vatican City. The small terracotta sculpture represents "Charity" breast-feeding a child, with three other children playing. There is an imprint of the artist's thumbprint in the clay.
Document 6: Bust of Pope Gregory XV: The Bust of Pope Gregory XV is a marble portrait sculpture by the Italian artist Gian Lorenzo Bernini. Executed in 1621, the work is one of three busts of the subject created by Bernini—the other two were bronze casts. The marble bust is on permanent display at the Art Gallery of Ontario. It was donated to the museum by Joey and Toby Tanenbaum.
Document 7: Aeneas, Anchises, and Ascanius: Aeneas, Anchises, and Ascanius is a sculpture by the Italian artist Gian Lorenzo Bernini created c. 1618-19. Housed in the Galleria Borghese in Rome, the sculpture depicts a scene from the "Aeneid", where the hero Aeneas leads his family from burning Troy.
Document 8: A Faun Teased by Children: Bacchanal: A Faun Teased by Children is a marble sculpture by Italian artists Gian Lorenzo Bernini and his father Pietro Bernini. It was executed in 1616 and 1617, when Gian Lorenzo was not yet twenty years old. It is currently in the Metropolitan Museum of Art in New York.
Document 9: The Goat Amalthea with the Infant Jupiter and a Faun: The Goat Amalthea with the Infant Jupiter and a Faun is the earliest known work by the Italian artist Gian Lorenzo Bernini. Produced sometime between 1609 and 1615, the sculpture is now in the Borghese Collection at the Galleria Borghese in Rome.
Document 10: The Rape of Proserpina: The Rape of Proserpina () is a large Baroque marble sculptural group by Italian artist Gian Lorenzo Bernini, executed between 1621 and 1622. Bernini was only 23 years old at its completion. It depicts the Abduction of Proserpina, who is seized and taken to the underworld by the god Pluto.
Document 11: Bust of Cardinal Giovanni Dolfin: The Bust of Cardinal Giovanni Dolfin or Delfin is a sculptural portrait by the Italian artist Gian Lorenzo Bernini, which is part of a mausoleum for the Venetian Cardinal Giovanni Delfin, member of one of Venice's most ancient noble families. The tomb as a whole was a joint work commissioned of Bernini and his father Pietro. While Gianlorenzo executed the portrait bust, Pietro carried out the surrounding figures, including two allegorical figures of Faith and Hope as well as the Delfin family coat of arms. The work was completed in late 1621, and sits in the church of San Michele in Isola.
Document 12: Bust of Giovanni Vigevano: Bust of Giovanni Vigevano is a marble sculptural portrait by the Italian artist Gian Lorenzo Bernini. The bust was produced between 1617 and 1618, and was then inserted into the tomb for Vigevano after he died in 1630. The tomb is in the church of Santa Maria sopra Minerva in Rome.
Document 13: Elephant and Obelisk: The statue is a sculpture designed by the Italian artist Gian Lorenzo Bernini. The elephant was probably executed by his assistant Ercole Ferrata; the Egyptian obelisk was uncovered during nearby excavations. It was unveiled in February 1667 in the Piazza della Minerva in Rome, adjacent to the church of Santa Maria sopra Minerva, where it stands today.
Document 14: Martyrdom of Saint Lawrence: Martyrdom of Saint Lawrence is an early sculpture by the Italian artist Gian Lorenzo Bernini. It depicts the saint at the moment of his martyrdom, being burnt alive on a gridiron. According to Bernini's biographer, Filippo Baldinucci, the sculpture was completed when Bernini was 15 years old, implying it was finished in the year 1614. Other historians have dated the sculpture between 1615 and 1618. A date of 1617 seems most likely. It is less than life-size in dimensions, measuring 108 by 66 cm.
Document 15: Sleeping Hermaphroditus: The Sleeping Hermaphroditus is an ancient marble sculpture depicting Hermaphroditus life size. In 1620, Italian artist Gian Lorenzo Bernini sculpted the mattress upon which the statue now lies. The form is partly derived from ancient portrayals of Venus and other female nudes, and partly from contemporaneous feminised Hellenistic portrayals of Dionysus/Bacchus. It represents a subject that was much repeated in Hellenistic times and in ancient Rome, to judge from the number of versions that have survived. Discovered at Santa Maria della Vittoria, Rome, the "Sleeping Hermaphroditus" was immediately claimed by Cardinal Scipione Borghese and became part of the Borghese Collection. The "Borghese Hermaphroditus" was later sold to the occupying French and was moved to The Louvre, where it is on display.
ground_truth: Pietro Bernini
sub_queries: The Memorial to Ippolito Merenda was made by whom? Answer: Gian Lorenzo Bernini
Gian Lorenzo Bernini >> father Answer: Pietro Bernini