Born in Lipova, Arad County, in the Banat region, his father Ion Marian was a trader, while his mother Persida (née Șandor) came from Nădlac.
After completing the Romanian-language primary school in his native town in 1842, he enrolled in the Minorite gymnasium of Arad.
[7] Over the ensuing years, Marienescu contributed to numerous publications, mainly from Transylvania: Foaia pentru minte, animă și literatură, Gazeta de Transilvania, Familia, Telegraful Român, Aurora română, Albina, Almanahul Societății de Lectură "Petru Maior" (Budapest), Amicul școalei, Analele Academiei Române, Aurora română, Calendarul diecezan, Columna lui Traian, Concordia, Dâmbovița, Educatorul, Ethnographia, Ethnologische Mitteilungen aus Ungarn, Federațiunea, Foișoara Telegrafului român, Gazeta poporului, Luminătorul, Naționalul, Opinca, Romänische Revue and Transilvania.
[8][1] While a student in Pest, he diligently researched archives and libraries for historic and topographic data related to the origin of the Romanians.
Balade culese și corese and Colinde, were published with funds donated by Andrei Mocioni and received an enthusiastic endorsement from Iacob Mureșianu.
Balade culese și corese appeared in 1867, followed by Doi feți cotofeṭi sau doi copii cu părul de aur (1871), Seran și Zoran (1872) and Steaua Magilor sau Cântece la Nașterea Domnului Isus Cristos (1875).
[10] He was described by Ovidiu Bârlea as a "notorious polymath" who "delved into nearly every branch of the humanities: literature, history, ethnography, folklore, political economy" and became "Transylvania's first important folklorist".