After rallying with a larger conservative coalition, he served a final ministerial term in 1856, became a minor contender in the princely election of 1859, and was Vice President of the resulting Ad hoc Divan.

[7] An anonymous letter, tentatively dated to April 1821, cites him as one of the boyars attracted into the anti-Phanariote faction of this diaspora, alongside Grigore Brâncoveanu, Scarlat Rosetti and Alexandru Vilara.

[9] In 1828, under Grigore IV Ghica, he issued the first-ever decree regulating Wallachia's police, which also marked a first step in its transition to modern metropolitan law enforcement.

From within the Ordinary Assembly, Cantacuzino supported tagging the controversial "additional article" to Regulamentul, and thus revealed himself as a vocal backer of Russian influence in the Principalities.

"[42] In early October, Fuad communicated to Cantacuzino the guidelines he had been issued by Abdulmejid I: "his imperial majesty the sultan has persistently recommended that I erase all trace of the revolution.

[44] His acts became the topic of a protest, submitted to Âli Pasha, the Ottoman Foreign Minister, by revolutionary agents Ion Ghica and Abdolonyme Ubicini.

[45] By then, the Revolution's triumvirate of Princely Lieutenants had dispersed: though Christian Tell and Nicolae Golescu suggested armed resistance, Ion Heliade Rădulescu resigned and retreated to his home, leaving the palace to be taken by Ottoman soldiers.

[49] Assigning the direct supervision of education to Băleanu, Filipescu-Vulpea, and Petrache Poenaru, he initiated the purge of radical teachers, and, on November 1, personally ordered for all schools to be shut down.

[54] Instead, the Caimacam made sure the border with Hungary to be fully closed, in hopes of preventing revolutionary exports; his orders resulted in the arrest and expulsion of Magheru's wife, who had attempted to return to Wallachia.

[58] The Caimacam stood accused of orchestrating the ransacking of Heliade's home[59] and of various acts of cruelty, including being seen as responsible for the prison death of poet Ion Catina, which his regime tried to conceal.

[61] Though he endorsed additional clampdown measures, Cantacuzino was a moderate in this respect: Colonel Grigore Lăcusteanu, who organized the round-up, recalls that Fuad ordered him to limit the scope of his investigations, and also to submit to the Caimacam's every command.

[65] A month later, however, Cantacuzino was preparing judicial procedures against all those who had protested against the Ottoman invasion—as reported at the time by Colquhoun, this would have resulted in sentencing for a great many Wallachian youths.

[71] His municipal policies blended with repressive measures when he demoted Alexandru Orăscu, previously Bucharest's council architect, and promoted Xavier Vilacrosse.

[72] He also staged an inquiry into Iacob Melic's activity as a revolutionary architect, ordering him to pay back sums he owed to the city government of Bucharest and to Clucer Barbu Catargiu, and sequestering some of his assets.

[75] As argued by military historian Theodor C. Văcărescu, Cantacuzino "governed in name only", with real power being exercised by Fuad and, to a lesser degree, by Russian commissioner Alexander von Lüders.

[76] During the Cantacuzino regency, and without Ottoman consultation, Wallachians were made to pay for the upkeep of Russian troops, with earlier tributes being increased by 20% for the 1848 fiscal year.

[82] As early as November 1848, he had presented himself as a candidate for the Wallachian throne—though, as noted by the Piedmontese diplomat Francesco Mathieu, neither he not Bibescu stood a chance against Știrbei, the Ottoman favorite.

[93] As Știbei's Vornic or Interior Minister in 1849–1850, Cantacuzino introduced more leniency toward imprisoned liberals, assessing pleas for amnesty and reporting on revolutionary Tănasie Macovei's sufferings from scrofula.

[95] According to the Știrbeist Ioan Maiorescu, the Vornic was helping the Russians prolong their occupation by sponsoring a false-flag rebellion; Știrbei, realizing the scope of the intrigue, responded by deposing his own cabinet.

[96] In June 1851 Cantacuzino and his rival Bibescu were both visiting the French Republic, both of them courting the Wallachian revolutionaries in exile, ostensibly to win their support for their own candidacies for the throne.

[101] Also in early August, Cantacuzino welcomed in his home Halim Pasha, whose small expeditionary force restored an Ottoman presence in Bucharest; Austria's consul Anton Ritter von Laurin was also present.

[106] On August 31, Dervish Ibrahim Pasha partly satisfied Cantacuzino's request, appointing him and Constantin Năsturel-Herescu to lead a provisional government which was to handle affairs until Știrbei's promised return.

[109] Grigore Cantacuzino was included in this administrative apparatus: with Sadyk and Carol Davila, he took measures to control the cholera epidemic, earning kudos from the Ottoman overseers.

"[114] On September 9, Wallachian patriots, including Cantacuzino, organized in Bucharest a grand ball in honor of Sadyk and Iskender—a French observer, Eugène Jouve, viewed this as a tactless display, since the presence of both Pashas was "more insulting to Turkey's allies than to her enemies.

[120] In September, he wrote indignantly that Cantacuzino Sr was paying Carol Sweder to publish seemingly independent praise of him and his defunct regime in Journal de Francfort, Der Wanderer, and other papers of the German Confederation.

[122] That year, the revolutionary exile Dimitrie Bolintineanu published his political tract, L'Autriche, la Turquie et les Moldo-Valaques, which contended that Cantacuzino was incompetent and unreliable when it came to supporting the Western powers.

[129] Both father and son took seats in the Divan (or Elective Assembly): Aga Ion was reelected at Prahova, while the former Caimacam took the boyar vote in Teleorman, along with Ioan Slătineanu and Serdar C.

As Vice President of the Assembly, Constantin validated the election, noting that there was no legal act preventing Moldavians to be put up as candidates;[133] he also signed the address which sought to obtain Cuza's recognition as Domnitor.

[138] Around mid-1864, Cantacuzino the elder was still residing in Bucharest, receiving there visits from Arthur Seherthoss, who represented the Hungarian National Directorate, trying to gather support for a rekindled struggle against Austria.

Ion remained especially prominent as a minister of the United Principalities, and from 1863 one of Cuza's leading conservative opponents;[143] his youngest brother, Adolf Cantacuzino (married to Ecaterina Iarca), was inaugural President of the Court of Appeals.