1. Architecture in the Duomo
2. The Façade
3. The Spires

1. Architecture in the Duomo
The Duomo is a unique monument in the vast scenery of Gothic cathedrals.
Gothic architecture originated in France thanks to the climate of economic welfare, which resulted from the flourishing of agriculture, crafts, commercial exchanges (traders and bankers), and to particular political-social circumstances.
The first example of the organic and rational use of separate structural Gothic elements in a new decorative and static system, signs of which could already be seen in the churches dating back to the period of Romanesque maturity, is the reconstruction (ca. 1140) of the abbey church of Saint Denis, commissioned by the Abbot Suger. Soon, the Gothic cathedral building sites of Ile-de-France spread throughout France, Germany and Bohemia and later to England and Spain. In Italy, Gothic developed in the central regions almost one century later, mainly in Tuscany and Umbria, but with more balanced structural features and with a decorative display of the subjects that was less dramatic and less redundant in its expressive forms.
The Duomo of Milan rose when the Gothic style of cathedrals was at its height.
The new cathedral, wanted by the Archbishop Antonio da Saluzzo and supported by the Prince of Milan, Gian Galeazo Visconti, was designed according to the stylistic features of Lombard Gothic, a more formal than substantial transcription of the Lombard Romanesque style, from which it inherited the constructive experience, the structural choices and the traditional material: fired brick.
In the second half of 1387, Prince Gian Galeazzo Visconti decided to personally oversee the project, in order to affirm the political prestige of his Signoria in Europe, making the Duomo the universally recognized status symbol of his rule. He therefore established the Veneranda Fabbrica to design and erect the Cathedral, which was to be built like the solemn and inspired grand churches that rose in the capitals and major cities of the stable and flourishing kingdoms and princedoms beyond the Alps. The new typology required the use of a different material: marble, which Gian Galeazzo guaranteed the supply of by placing the quarries of Candoglia at the Fabbrica’s disposal.
Many Campionese masters joined the local architects already present at the site. The need for engineers, architects, sculptors and stone-cutters with experience in central-European Gothic demanded that the Fabbrica search for them at sites throughout Europe. For about twenty years, hundreds and hundreds of foreigners joined local workers making suggestions, bringing their experience, cultural abilities and different manual skills. This is how the unique Gothic style of the Duomo originated. It was surely based on transalpine Gothic, particularly on the Rhenish and Bohemian styles, which were taken as examples to imitate in the verticality of the structure, the spatiality of the inner volume and the bizarre sculptural decoration.
For the Duomo site, these were the decades of greatest splendor. It became the place where different European cultures blended together, in a lively space of exchange of different ideas, experiences and manual abilities expressed by workers coming from the regions whose boundaries were marked by the Pyrenees and the Carpathians.
During those years, the European labor force experienced the massive immigration of thousands of workers from north to south in order to give their contribution to the construction of the Milanese cathedral, which for this reason can be considered the most European among all Gothic cathedrals.
When the influx of foreign labor ended in the second decade of the 15th century, in spite of the different rhythms imposed by the circumstances (political, military, economic, and of public safety) of Milan and its countryside, the Fabbrica’s site carried on according to the adopted standards. It remained always loyal to the “principle of conformity to Gothic,” at least until the arrival in Milan of the Archbishop Carlo Borromeo (1565) and his architect, Pellegrino Pellegrini (1567). With the decrees of the Council of Trent (1563) came the start of the Counter Reformation – or better, the Catholic Reformation – in response to the Protestant Reformation. With this in mind, the Archbishop Borromeo drew inspiration for the new undertakings in the Duomo from the architectural ideas and shapes of the ecclesiastical furnishings of papal Rome and from the fully-developed late-Michelangelesque classicism. This was meant to be a sign of unity of the Milanese Church with the Church of Rome and a visible acknowledgement of the close relationship with the Petrine primacy. Despite the tempered disapproval of the Fabbrica, St. Carlo gave a new imprint to the interior of the Duomo, especially to the parts that were functional to the liturgy: the magnificent architectonic structure of the presbytery, the side altars, the crypt, the baptistery, and the floor. St. Carlo’s approach imposed itself and was then followed by his successor, Cardinal Federico Borromeo, in the first projects for the façade (portals and windows) by Pellegrino Pellegrini (1590-91) and Francesco Maria Richino.
Following the death of the two Borromeos and the gradual lessening of their spiritual and cultural influence, the Fabbrica’s loyalty to Gothic did not take long to steer its choices. The façade, though maintaining the lower portion built following the Counter-Reformation projects of Pellegrini and Richino, was reintegrated with the Gothic architecture of the sides featured in the project by Carlo Buzzi (1645), which was resumed and completed in its general planning by Carlo Amati (1807-14). However, the latter changed and simplified the project, making the architecture more static and less spiritual in its decorative display, clear evidence of the influence of Neoclassicism. A similar stylistic shift had occurred about forty years earlier (1765-69), when the dome was completed by the main spire that rose at the center of a double crown of slender spires and reverse flying buttresses. It is not difficult to recognize in them the graphic patterns, the incisiveness and the dynamism of late-Milanese Baroque.

2. The Façade
When it came time to finalize the Duomo’s structure and formal definition, the architects surely did not neglect the façade, whose design was still very far from what was in the process of being built.
For many years, the façade of the basilica di Santa Maria Maggiore was used as a temporary solution, which the new cathedral would have progressively replaced by demolishing it as work progressed.
When St. Carlo arrived in Milan (1565), the construction of the Duomo had reached the fifth span and the nave was still closed by the façade of Santa Maria Maggiore.
There is no evidence of a drawing by Pellegrino Pellegrini during the episcopacy of Carlo Borromeo, even if the matter of the cathedral façade had surely been outlined by the archbishop during his meetings with his trusted architect.
1590 marked the beginning of the “Roman-style” season, expression of a classical architectural language which, in adherence with the choices of Carlo Borromeo, underlined the loyalty of the Ambrosian Church to the Apostolic See in a time when Protestant pressure at the borders of the Milanese diocese was very strong. However, at the same time, it contradicted the principle of “conformity with Gothic,” which the Fabbrica had always consistently honored.
In 1609, after having examined many designs presented during the last decade of the 16th century, Federico Borromeo decided, for the first order, to follow Pellegrini’s model (1592) and resume the construction work, which was interrupted at the lower windows with the death of Borromeo in 1630, according to the projects designed by the architects Fabio Mangone and, later, Francesco Maria Ricchino.
Starting in 1630, the Milanese cultural and religious climate changed considerably: the reformist tension had diminished as did the love for classicism that the Borromeo’s held so dear, so much so that, for the continuation of the Duomo works, it was decided to resume the Gothic forms and adhere with the original stylistic choices. This led to the drafting of the projects by the architect Carlo Buzzi (1645-53) which preserved what had already been built in “Roman style,” such as the portals and windows.
In 1653, the Fabbrica Council chose the last project designed by Buzzi over that of Francesco Castelli.
However, this did not prevent the Council members from pressing for new solutions for the façade: a new, long phase of discussions generated further suggestions for designs presented by an anonymous Jesuit priest and Antonio Maria Vertemate Cotognola.
It was only in 1683 that the demolition of the 15th century old façade and the construction of the wall structure of the new one began, even though the matter of the choice of a final project remained unsettled until 1790. It was in that year that the Chapter chose the project by Felice Soave, which drew from the plan by Carlo Buzzi but in a more simplified way. Beginning in 1791, work had begun again following the latter design.
The completion of the façade dates back to the years of the Kingdom of Italy during the Napoleonic era and is owed to the initiative of Napoleon Bonaparte himself. The king’s wish, expressed at the eve of his coronation and in the decree of June 1805, introduced to the project Amati-Zanoja who, with the aim of preserving the architectural structures that had already been built – the pillars that line the façade dividing it into five sections, the main and side portals, and the four windows of the upper order – placed upon them a typically Lombard gabled crown, corresponding to the decreasing course of the inner arches. Three large ogival windows were then inserted in the three central sections together with a passageway featuring suspended arches that dip near the sloping brim of the roof.
Presented on January 1st, 1807, the project became operational. Works were completed in 1813.
The current façade, fruit of the eclectic mixture of many projects, underwent further work with the modification of the embrasure, which completed it in 1932.

3. The Spires
The profile of the Duomo, which can be seen silhouetting against the background of the city – even from afar – becoming its essential symbol, features one hundred and thirty-five spires.
The spire is a typical element of Gothic architecture, especially ecclesiastical, for the immediate and inspiring charge of spirituality that it transmits as it soars toward the sky. It was conceived not so much as embellishment but rather as an element participating in the static structure of the architectural whole. In fact, with virtually non-existent axial weight on the perimetric buttresses, the spire weighs on the latter above the point where the cross vaults meet, thus contributing to containing the horizontal thrusts that would tend to divaricate the bearing structures. With this function in mind, spires were initially modest in height, quite thick – at times more similar to a turret or small belfry – and compact, and with a sturdy section. It was only at the end of the 12th century that static and decorative effects were combined. With time, it took on soaring lines becoming pointed and elaborately decorated, with the addition of niches, pediments and small pyramids and, at times, statues.
With the exception of the Duomo, in Gothic cathedrals spires usually rise from the buttresses and are found only along their perimeter. There can be one or two very tall large spires at the front, acting as steeples. At times there may be two smaller spires bordering the apse. Often, at the center of the main cross or of the dome, a tall, very slender and purely symbolic spire is placed as a decorative complement.
Only the Duomo of Milan features such a large number of spires: one hundred and thirty-five. They are featured not only along the perimetric buttresses, but also atop each internal vertical bearing structure (pillars) and on the entire dome, where with an elegant game of static balance, they form a crown around the main spire, the one that supports the Madonnina. The spires are rich with ornaments and statues of every size – of which there are more than 1,800 – niches and openwork, giving it a particular plastic effect that increases with the variable vibration of light-and-shade. Most of the spires are 17 meters tall. However, there are shorter ones, such as those rising from the four pillars of the dome.
We can assume that the great number of spires comes from the desire to recover outside, toward the heavens, the spiritual tension – typical of Gothic – of the Duomo’s internal vertical structures, interrupted by the horizontal cornices of the section capitals, the main and side portals and the four windows of the upper order.