Catargiu was appointed to the position of minister of finances by Alexandru Ioan Cuza. He quickly gained acclaim for his oratorical skills, and became the focal point of the Conservative Party. He did very little to actually organize the party, instead depending on his own charisma and ideals to give the party focus. Cuza, despite not agreeing with the conservative doctrine and even seeing Catargiu as an adversary of sorts, recognized his abilities and the power of his followers and chose Catargiu as prime minister of the newly formed union between Wallachia and Moldavia.