Saving Michelangelo's Dome: How Three Mathematicians and a Pope Sparked an Architectural Revolution

“Kalayjian keeps suspense in his entertaining story in telling what might have otherwise been a dry history.”

Among the current historical fads is Michelangelo di Lodovico Buonarroti Simoni, primarily remembered for the ceiling of the Sistine Chapel but also for his statue of David and the great dome atop the Basilica of St. Peter in Rome. He lived to a great age, was recognized for his genius and talent in biographies in his own time, and left serious documentation for weaving amazing history in incredible times of world progress.

Wayne Kalayjian takes on the story of the dome in Saving Michelangelo’s Dome: How Three Mathematicians and a Pope Sparked an Architectural Revolution. This forgotten story of how the structure was saved 150 years later is almost as interesting as the building of the massive structure itself.

As is often the case, the facts are different from popular history. Building the dome had been a desire of four popes before Michelangelo. This great master of sculpture was responsible for the spectacular edifice seen today but his work began with a design that originated with Donato Bramante. Michelangelo designed this structure in his seventies, and he did not build it.

Kalayjian keeps suspense in his entertaining story in telling what might have otherwise been a dry history. Saving Michelangelo’s Dome is principally about restoring the dangerously decrepit structure but also about building it and other related topics. Consequently, this book is really two different works in a mixed narrative.

Some readers will find Saving Michelangelo’s Dome disjointed because the history is told not chronologically but in a more subject-explanatory manner. The author digresses with such topics as the contributions to the scientific revolution by Galileo, Newton, and others.

All this history is complicated, but Kalayjian keeps the prose, and the book, concise and a fast and engrossing read. The dome was a marvel in a 2,000-year-old history of Vatican Hill (Vaticanus Mons). Emperor Caligula built a chariot racetrack at the base of the hill, and, after St. Peter’s execution, a cemetery grew up on the site.

Begun as a grand edifice under the Emperor Constantine in 318 CE, St. Peter’s Basilica subsequently became the endless subject of modifications and expansions over 200 years and under 17 popes. Most of these schemes were never carried out, however.

As a sacred place, the site was always an obstacle to change, as was the turmoil of the Reformation and the religious wars in Europe. The characters of some of the popes further hindered the building of the complex. Kalayjian writes that “It is a miracle that St. Peter’s Basilica was ever finished.” The complete renovation of St. Peter’s was consecrated by Pope Urban VIII in 1626.

Michelangelo had worked on many parts of the Basilica before he was finally asked by Pope Paul III to build the dome. The elderly genius died in 1564, however, and the dome was completed by Giacomo della Porta and Domenico Fortana in 1593.

Kalayjian writes how the part of the work that was done at a “breakneck pace might have undermined and compromised the dome’s structural integrity.” Exactly why the dome developed so many cracks by 1740 remains an open question. Reasons include Constantine’s choice of a site for St. Peter’s in 318.

The author begins the book with the election of intellectual and kind, self-deprecating Prospero Lorenzo Lamberti as Pope Benidict XIV by the College of Cardinals on a record 225th ballot in Michelangelo’s celebrated Sistine Chapel, and under the crumbling dome, in 1740. A hard working, multi-talented Renaissance man from a prominent Bologna family, Lamberti was “an elite and respected luminary across the Papal States.”

Benidict XIV continued the progress begun under his immediate predecessor. Pope Clement XIII, who had founded the Capitoline Museums and made numerous civic improvements across Rome. The new pope, however, had to deal with heavy debts, war, and the intrigues of Italian city state politics.

The Church had ceased its punitive policies against the Protestants but “it had lost much of its moral authority, political clout, and international standing along the way.” This crisis came as the Renaissance had ended and the Enlightenment began, two eras that came out of the Church’s powerful intellectualism but also questioned the justification for its existence.

Then there was the dome, which was almost 25 stories tall and weighed 33,000 tons. With hundreds of cracks, rumors swirled “that this architectural jewel of the Roman Catholic Church might weaken and possibly collapse.” It “was a political emblem of the Papal States” and “an enormous, high-stakes problem.”

Similar situations occurred with the other great domes, such as the Hagia Sophia and the Santa Maria del Fiore. Yet no obvious solution for a fix existed, and earthquakes raised even more concerns by 1742. Kalayjian describes step by step the process for building such domes, and the measures that Benedict XIV did to solve his dome problem, starting almost immediately after becoming pope.

The pope’s different commissions and experts learned “that there is nothing simple about a dome,” such as how “the way that it absorbs and distributes its thrusting force” cannot be predicted. There were also “quirks of construction” and “peculiarities in means, methods, and materials” to consider.

The solution proved to be Luigi Vanvitelli, “a capable architect” with deep experience in working in the complicated world of the Vatican. His success owed much to mathematician priest professors Roger Joseph Boscovich, François Jacquier, and Thomas Le Seur.

The initial report of these young products of the Enlightenment “was different from anything that had been previously published on the design and construction of buildings.” They would “unify the communities of science and mathematics with the everyday world” in their “imaginative” investigation into the cause, not just the repair, of the cracks in the dome.

Benedict XIV faced numerous critical problems in his time as pope. His enlightened ideas and skilled leadership, however, saw that the structure was repaired, and the costs covered, by 1748, as only one of many successes in his papacy. Kalayjian writes of him as a highly successful leader with an impressive “legacy, influence, and imprint on Western culture.” The pope even kept his sense of humor!

Saving Michelangelo’s Dome has annotation, a bibliography, and illustrations, many in color.