February 6] 1919) was a Romanian socialist militant and politician, a leading member of the Social Democratic Party of Romania (PSDR) and labor activist.

Frimu was part of the leadership, as were Ioan Nădejde, Vasile Morțun, Constantin Dobrogeanu-Gherea, Alexandru Ionescu, Christian Rakovsky, Dimitrie Marinescu and Ilie Moscovici.

[3] Around that time, he met the tailor and socialist sympathiser Rozalia (also known as Rozica), a Transylvanian-born orphan who had settled in Bucharest during her late teens, and whom he married in 1901.

[4] In 1909, I. C. Frimu and the future novelist Panait Istrati were imprisoned at Văcărești Prison, after taking part in riots asking the National Liberal cabinet of Ion I. C. Brătianu to receive Rakovsky back into Romania.

[5] On January 31, 1910, when the PSDR was founded, Frimu, Rakovsky (who had been allowed to return), Gheorghiu Bujor, Dimitrie Marinescu, and Constantin Vasilescu were elected among its leaders.

On December 6, 1918, typesetters from the Sfetea and Minerva graphic design studios went on strike demanding better working and living conditions (a pay raise, an eight-hour day, etc.).

From inside the passage, General Mărgineanu placed a telephone call to Prime Minister Ion I. C. Brătianu, asking for his authorization to intervene against the demonstrators.

Important figures from the cultural, artistic and political realms, such as Ioan Slavici, Nicolae Tonitza, and Gala Galaction, harshly condemned the government's repressive action.

During the trial, the royal commissioner could not produce proof to back up his opening statement and thus the indictments, except against the Communist agitators, whom the Martial Court sentenced to 5 years imprisonment.

[10] As a result of beating and torture by police during his arrest, Frimu's liver and kidneys were heavily damaged, as reportedly indicated by the physician Cristodulo, who was the last to consult him.

Ion G. Duca, who was then in government, wrote that "the police arrested all the [strike] movement's leaders and beat them so severely that one of the most important socialists, Frimu, died a few days later due to the wounds he received".