The palace remained the personal property of the Colonna family until 1916, when it was given in perpetual emphyteusis to the City of Marino, which installed the municipal headquarters there.

[11] Thus, one can well understand the military importance of the fief, which was endowed with a new gate[12] - Porta Giordana, probably dedicated to the feudal lord Giordano Orsini -, a new urban addition[12] -the so-called Camere Nuove- and the defensive complex at the foot of the castle,[12] along the valley of the marana delle Pietrare.

Important personalities who stayed in the fortress before it was redesigned include Agnese di Montefeltro, wife of Fabrizio I Colonna -who stayed almost continuously in Marino between 1489 and 1523[17]-, Vittoria Colonna -who was born there in 1490 or 1492[17]-the king of France Charles VIII of France and the son of Pope Alexander VI Cesare Borgia (1495),[16][17] Alfonso I d'Este (1519),[16] Hugo of Moncada, viceroy of Naples and Sicily (1526).

[16][18] Throughout the fifteenth century the castle was the subject of alternating conquests by papal, Neapolitan or Colonnese armies: the climax was reached when in the summer of 1501 the French army marching toward Naples, led by Marshal of France Robert Stewart, received orders from Pope Alexander VI to raze the fortifications of Marino, Zagarolo, Artena, Genazzano, Paliano, Subiaco, Cave, Rocca di Papa and other fiefs belonging to the Colonna family, his personal enemies.

[16] Another destruction was suffered by the castle in November 1526 on the orders of Pope Clement VII as part of the devastating conflict that ended with the sack of Rome in 1527.

[16][19] Popular rumor has it that, in the work of rebuilding the baronial residence, the feudal lady Agnese di Montefeltro, a cultured woman who had grown up at the Montefeltro court in Urbino, also consulted the famous architect Donato Bramante, who was engaged at the time in the construction of the basilica of St. Peter in the Vatican in Rome, and that Bramante is credited with the construction of a section of scarp walls in peperino blocks located on the southwest front of the palace.

[21] Thus was conceived the straight line that from the via Castrimeniense -main road connecting with Rome, still today- led directly to the baronial residence under construction, through the gutting of the current via Roma through the upper-medieval district of the Castelletto ward.

[21][22] The triggering event for this urban renewal was probably the visit to Rome of Emperor Charles V of Habsburg,[22] Ascanio Colonna's father-in-law as the father of his wife Giovanna d'Aragona, from whom he later separated, maintaining conflicting relations.

[13] The difficulties Ascanio encountered under the pontificate of Pope Paul III[24] caused work on the palace complex to be suspended, which was resumed under the rule of Marcantonio II Colonna, famous because he was the admiral of the papal fleet at the Battle of Lepanto in 1571.

[21] Under the rule of the cardinal, who made himself disliked by the population for his authoritarian and despotic attitudes -so much so that in 1599 he stirred up a revolt of the people of Marino, which was violently quelled by the papal government army and the subject of a papal inquiry[27]- the Colonna Gardens complex was enlarged -causing quite a few protests among the people of Marino from whom the communal land used for growing onions was removed,[28] which became the splendid[28][29][30] private garden of the Colonna family -which was embellished with statues and fountains and with the frescoed vaults of the Casino, a new area of baronial greenery at the Ferentano woods, the Barco Colonna, was also created, and the part of the palace already laid out was finally completed.

The architect Antonio Del Grande, already active at the Palazzo Colonna in Rome and later at the parish church of Santa Maria Assunta in Rocca di Papa, was called to Marino to design the great[32] collegiate basilica of San Barnaba,[33] built between 1640[34] and 1662[34] at the end of the new thoroughfare already inaugurated at the end of the sixteenth century and currently called Corso Trieste.

Inside the ducal palace - in fact, since 1606 the fiefdom of Marino had been elevated to the rank of a duchy by Pope Paul V[36] - Filippo I Colonna entrusted the work to the architect Girolamo Rainaldi,[21] who arranged for the quadrangular tower in the center of the inner courtyard, on which the Colonna-Tomacelli coat of arms[20] still stands today; probably at this time the spiral staircase leading from the atrium on the ground floor to the main floor was defined, between 1619[13] and 1622.

[20] On the main floor, a number of paintings attributed to Taddeo Zuccari and his brother Federico Zuccari[20] were collected, forming a valuable but indefinable picture gallery to this day -dispersed not only by the war events of 1944,[37] but also by disposals and removals put in place earlier,[13] such as the transportation of the most valuable works to the residences of Paliano and Genazzano that took place in the mid-nineteenth century[38]-along with oleographs of the Popes with life-size reproduced heads[38] from St. Peter's to follow,[20] preserved until 1915 in the atrium on the ground floor.

[40] On December 11, 1812, nine brethren of the archconfraternity of San Giovanni Decollaro arrived in Marino called as spiritual assistants to some condemned prisoners whose sentence was to be carried out shortly thereafter: the nine men asked for hospitality at the palace, and received a magnificent one.

The subversion of feudalism, already declared by the French in 1807, was confirmed in the territories of "second recovery" -Romagna, Marche and Umbria, which were returned to the pope by the Congress of Vienna only in the summer of 1815- while in Lazio it was effectively discouraged by the motu proprio of July 6, 1816.

Those who have lived through those moments know; those who have not lived through them ... cannot understand.On February 2, 1944, in the midst of World War II, the building was almost entirely destroyed by the first Anglo-American aerial bombardment carried out over the historic center of Marino -previously, only the hamlet of Ciampino had been hit[53]- Despite the fact that the local National Liberation Committee presided over by the future servant of God, mayor of Marino and Christian Democrat senator Zaccaria Negroni, had informed the Allies of the absence of war objectives in the territory of Marino,[54] the raid was probably unleashed with the intention of striking the car park of Villa Colonna di Belpoggio and the base transceiver station of Palazzo Colonna.

[37][55] Under the palace, in the intricate maze of caves originally used as ducal cellars, displaced citizens found refuge throughout the war period.

[56] Around the rubble of the palace, after the arrival of the Anglo-American army between June 3 and 4, 1944, the pro tempore municipal administration and many citizen volunteers labored to make the city's fortunes rise again quickly: the moving account of the war and postwar period in Marino was provided by a protagonist of these years, Zaccaria Negroni, in the book Marino sotto le bombe.

On December 13, 1944, the temporary headquarters of the municipal middle school and the Paolo Mercuri State Art Institute were inaugurated in the premises of Palazzo Colonna that had survived the bombing.

As early as July 1954, however, the interior spaces of the palace were allocated: in addition to housing the municipal administration, the basement overlooking Lepanto Square would house a "wine store" and the pro loco, while the ground floor overlooking the inner courtyard was destined for the "Paolo Mercuri" state art institute, shortly thereafter officially recognized as a secondary school.

[60] Students of the art institute were also entrusted with the creation of peperino busts depicting some personalities linked to Marino:[60] among others Vittoria Colonna and Michelangelo.

[66] On Oct. 4, 2008, still in conjunction with the celebrations for the eighty-fourth Grape Festival, a delegation from the twinned Spanish town of Paterna was received in the council chamber.

Certainly, it is possible to trace in the style of this front a reference to the facade of Palazzo Farnese in Rome, currently the seat of the French embassy in Italy, designed by Antonio da Sangallo the Younger.

Since 1987, the premises of the palace facing Largo Palazzo Colonna have housed the Pro Loco association with its archives and the "Girolamo Torquati" library of local interest.

[62] In the center of the staircase is a niche, in which is placed a cipollino marble column[70] on an ancient pedestal, a symbol of the Colonna family and now also of the city of Marino.

[72] On one side is added the modern epigraph MOLE SUA STAT[72] (in Latin, "It stands by its own stature"), a motto of the Colonna family in reference to the column of the noble Roman lineage.

[21] For the western facade, the project included a terraced front open to the southwest, with a view of the valley of the marana delle Pietrare and the peperino quarries.

On the western side, largo Luigi Oberdan houses the headquarters of the Associazione Nazionale Perseguitati Politici Antifascisti and the Associazione Nazionale Partigiani d'Italia, and the stretch of peperino block walls probably dating back to the original 14th-century fortification of the Orsini fortress,[13] but whose design is attributed by tradition to the hand of architect Donato Bramante, called by Fabrizio I Colonna's wife Agnese di Montefeltro, feudal lord of Marino between 1489 and 1523.

Today, a great peace, as though of sleep, breathes over the whole town and it seems that it rests from the bitter events and past hardships.The inner courtyard was established only during Girolamo Rainaldi's interventions in the early 17th century,[21] with the construction of the portico and quadrangular tower.

Inside the courtyard are several archaeological artifacts that have survived from the old municipal antiquarium, such as a fragment of a relief with peperino trophies dating from the first century B.C.,[74] a 1st-century coarse-grained white marble entablature block with an epigraph found in the Pantanelle locality referring to personages of the gens Bellicia,[75] a 3rd-century coarse-grained white marble sarcophagus,[76] a 4th-century entablature block found in the Costa Rotonda locality, and probably referable to a fund owned by Constantine I the Great or his sons,[77] the upper part of an 11th-century ogival mullioned window, probably from the former church of Santa Lucia,[78] which was deconsecrated in the second half of the 17th century and now houses the Umberto Mastroianni Civic Museum.