When De Melo departed Manila in November 1597, he brought Nicola, an 18-year-old Japanese convert whom he baptized, and his namesake - Nicolás de San Agustín. Their ship passed through Macau and Malacca but not until 1598 did the monks arrive in Goa and met Aleixo de Menezes. For another year, ships would not depart for Portugal due to the change in season. The priests made the decision to pass through the Safavid realm as a result. Alfonso Cordero was requested to join them by Simon, the bishop of the Church of St. Francis, when he was in Goa.
In February 1599, the monks departed from Goa and arrived in Hormuz. The priests traveled to Isfahan after learning that the new Spanish king's envoys had reached Shah Abbas's palace in Hormuz. But it wasn't until they got to Isfahan in April that they discovered these ambassadors were English Shirley brothers, not Spanish. They had met the Shah through a Venetian named Giacomo Fava, who had been to Iran the year before. Here, Melo encountered the English adventurer Anthony Shirley, who was leading an embassy on behalf of Shah Abbas I to the courts of Christian Europe, seeking to form a military alliance against the Ottoman Empire. Melo managed to join this diplomatic mission, carrying letters from the Shah to both the Pope and King Philip III of Spain. He sent informative letters to Antonio Fernández de Córdoba y Cardona (Spanish ambassador in Papal States) via Michel Angelo Corai.[2] Shirley viewed Melo as an asset, given his position and connections to the Spanish crown.[1] Shah Abbas, who entrusted the priest with embassies in Spain and Rome, inadvertently undermined the embassy's work. He was unfamiliar with European diplomatic practice, and when he presented credentials to the ambassadors, he made no distinction between who was the main ambassador. Shirley would later compete with Melo for the role.[5] As a result, the relationship between the two quickly deteriorated, allegedly due to Sherley's coveting of Melo's wealth, which included a significant sum of money and precious diamonds entrusted to him during the journey.[1]
The embassy crossed the Caspian Sea and arrived in Astrakhan, in 1599.[5] Here, Shirley reportedly felt emboldened to act against Melo, believing that the Portuguese friar had less influence under Russian rule.[6] Shirley had Melo imprisoned, confiscating his letters and possessions. According to various accounts, including that of Don Juan of Persia, Shirley attempted to kill Melo multiple times during their journey down the Volga River, but the friar was saved by the intervention of Safavid officials who had befriended him.[1][7]
In Moscow, Melo was placed under arrest again, and Sherley accused him of various crimes. Shirley accuses Melo of violating Christian morals in his memoirs, even claiming that he slept with prostitutes while in Isfahan. According to Arnulf Hartmann, these were defamatory rumors spread by an Armenian priest who was translating for Melo in Hormuz and wanted to be a member of the embassy.[8] During interrogations by Russian officials, Sherley allegedly struck Melo, further solidifying his hostile intent. Despite these actions, Melo continued to conduct his religious duties, including baptizing Lucia - the daughter (or granddaughter) of a Milanese doctor called Paolo[9] Cittadini[4] in Catholic rites which led to his eventual arrest. Cittadini was a personal physician to Feodor I of Russia.[10]
After five months of imprisonment in Moscow, Melo was deported to the Solovetsky Monastery in Northern Russia, a harsh prison during the reign of Boris Godunov. News reached to Iranian embassy when they were in Port of Arkhangelsk in July 1601. He remained there for six years under brutal conditions, enduring starvation, extreme cold, and physical abuse. Melo's suffering continued through the turbulent political landscape of Russia, which saw the rise and fall of several rulers.
In July 1605, three months after Boris Godunov died suddenly, False Dmitry took the throne in Moscow as the new Tsar. According to "Diary of Marina Mniszech", which was written by a Polish secretary of Marina Mniszech Melo was in contact with Dmitry's supporters.[11] After gaining temporary freedom during the rule of False Dmitry, thanks to John Thaddeus of Saint Eliseus, a Carmelite friar who was sent by Clement VIII[4] (or Paul V[1]). This decision did not occur immediately after Dmitry took power but later. By the time the two Nicolases returned from Solovetsky to Moscow, Vasily IV Shuisky was already in power.
The two were questioned once more in Moscow, this time with an English interpreter from the Muscovy Company. The two received "favorable" treatment, but were nonetheless sent into exile. Melo was sent to the Monastery of Sts. Boris and Gleb in Rostov. It was home to the renowned ascetic Irenarch, whom Melo probably befriended.[12] He was also in contact with Jerzy Mniszech, father of Marina Mniszech, who was now a widow.[4] Meanwhile, his Japanese companion, Fr. Nicolás de San Agustín, was eventually killed in September 1611, executed by beheading in Nizhny Novgorod.
He soon was freed by Ivan Zarutsky. Melo became the chaplain to Marina Mniszech, following her to Astrakhan by 1613. According to Pierling, Marina and her son Ivan Dmitriyevich were accompanied by three Catholic priests. These included Father Antonius of the Bernardine Order, who had shared Marina's fate since her arrival in Moscow, John Thaddeus of the Carmelite Order, who had been in Safavid Iran on a mission and had now returned via the Caspian Sea, and Nicolas Melo, who had joined them from Nizhny Novgorod. At this time, Barbara Cazanowsky, a Polish noblewoman who had accompanied Marina from Poland, converted to Catholicism and joined the Augustinian Order under Melo's guidance.[12]
In 1614, new tsar Mikhail Romanov's troops sailed down the Volga, approaching Astrakhan, seeing young Ivan as a potential rival. Zarutsky and Mniszech found themselves in a precarious situation and sent emissaries to appeal for assistance from Shah Abbas, seeking permission for asylum. However, in May 1614, Zarutsky, Marina, and several hundred Cossacks fled from Astrakhan, traveling along the northern coast of the Caspian Sea and entering the Ural River. On an island known as "Bear Island", Zarutsky's forces were surrounded by Romanov troops. On June 25, the Cossacks surrendered, handing over their leader Zarutsky and Marina with her son Ivan to the government troops.
