Ellen Adelaide Rasmussen was born on 7 January 1906, in the railway town of Skoerping, Nordjylland, Denmark. She was the fourth of ten siblings born to parents Rasmus Peder Edvard (1870-1939) and Ane Birgitte Christine Rasmussen (1878-1976). She was given the middle name of Adelaide to honor her paternal grandmother, Louise Therese Adelaide Rasmussen (1845-1904), who died a year and a half before her birth. Her father worked as a watchmaker, and the family moved to Copenhagen for his job.

In 1929, at the age of 23, she emigrated to Montreal, Canada to find work. It was here where she met her future husband, a fellow Danish emigrant named Carl Brandenborg, at a local church, and the two were married in 1930. The couple would have four children together (1 son and 3 daughters) before deciding to move back to Denmark in 1936, where Carl would find work in the town of Viby as a factory machinist. They would remain married for 52 years, until Carl’s death in 1982.

She attributed her longevity to living life in moderation, avoiding tobacco, eating lots of fruits and vegetables, and having good friends and family. Aside from a hip replacement surgery in 1980, she was never hospitalized, and was rarely sick. In 2013, at the age of 107, she voted in the municipal elections by mail for the first time, and emphasized the importance of voting, stating that “those who don’t vote are lazy”. She continued to live independently in her apartment until a few months before her 109^th birthday, when she decided to move to a nursing home. At the time of her 110^th birthday in 2016, her eyesight and hearing were poor, but she still maintained an active lifestyle and positive attitude. Her cognitive faculties had remained intact, and she was able to recall stories from her childhood.

Ellen Brandenborg died in Stavtrup, Aarhus, Midtjylland, Denmark on 22 July 2017, at the age of 111 years, 196 days. She was survived by three children, seven grandchildren, and nine great-grandchildren.