The Mērija Grīnberga Jr collection is a part of a bigger one, the Grinbergs-Grosvalds family collection. This family was one of the most prominent families in the political and cultural life of Latvian society until 1940. Members of the family include the painter Jāzeps Grosvalds (1891-1920) and the diplomat and art historian Oļģerds Grosvalds (1884-1962). Their sister Mērija Grīnberga Sr (1881-1973) was the founder and proprietor of a popular salon of applied arts in the 1920s and 1930s. Her son Emanuels Grinbergs, despite persecution during the Stalinist period, became a prominent mathematician. The collection of family artefacts, including material on Mērija Grīnberga Jr, was donated to the Museum of the History of Riga and Navigation in 1975-1977 by Emīlija Gadziņa, the wife of Mērija‘s brother Emanuels Grinbergs (1911-1982). Mērija Grīnberga Jr (1909-1975) worked in several museums from the late 1930s. From October 1944 to February 1946, she accompanied the most valuable items from the main Riga museum collections evacuated by Nazi Germany's state institutions to the Opava region in the present-day Czech Republic. Thanks to her efforts, most of the collection was preserved and returned to Riga, although she could not prevent the loss of some items through looting and transport (initially the collections were packed in approximately 700 boxes, she returned to Riga in February 1946 with 406 boxes). Her efforts were not acknowledged, she was interrogated by the security services, and in 1950 she was fired from her job at the museum, and had to work in a factory until 1958, when she found a job as a librarian in the State Museum of Latvian and Russian Art (now the Latvian National Museum of Art). There are several publications and a documentary about M. Grīnberga Jr. 'Mērija's Voyage' (Mērijas ceļojums) is in the process of shooting. She is often mentioned as a charismatic personality in recollections about the National Museum in the 1960s and 1970s, most recently in the novel 'The Museum' (2017) by Jānis Rokpelnis.