Suffragist. Aletta Catharina Lorentz-Kaiser was active in the early women's rights movement in the Netherlands, She was the youngest daughter of Johann Wilhelm Kaiser, who was a director of the Amsterdam's Engraving School and in 1881 was a professor at the Rijksakademie teaching Fine Arts. Her father also designed the first Dutch postage stamps. She was the wife of Nobel Prize recipient Dr. Hendrik Antoon Lorentz; they married in 1881 and had four children, with the youngest son dying in the first year of life. Their eldest daughter was the physicist Geertruida de Haas-Lorentz. She was the niece of Dutch astronomer, Frederik Kaiser. Dr. A. D. Fokker, who knew the couple, wrote "Aletta was a modest woman, perhaps somewhat strict in her views. The emerging trend for the emancipation of women found in her a convinced advocate and defender." She was a pioneer in the Dutch children's day care system for working mothers or those who were too ill to care for their children. She became secretary of the Association for the Care of Small Children, which established one of the first child day cares in the Netherlands. In 1893 she left the board. In 1904 she became a member of the board establishing a folk playground where children from poorer families were welcome regardless of faith. She and her husband were members of the moderate group, the Dutch Association for Women's Suffrage , which also admitted men to the board and had broken from the much radical suffrage groups. By 1911 she had resigned her administrative duties, as she moved to Haarlem in 1912 when her husband accepted a position there. She became active in the well-being of single mothers and responsibilities of the father of their children, asking for child support reforms. Mainly doing promotional events, she served on the committee of recommendations for the exhibition "The woman 1813-1913." This exhibition was held in Amsterdam from May 2, 1913 to September 30, 1913. According to the magazine "Evolution" of December 3, 1913, Aletta Lorentz was on the board of the Association for the Improvement of the Social and the Legal Status of Women in the Netherlands. One of her close colleagues was Lizzy van Dorp, the first woman to graduate with a law degree in the Netherlands.