Tekla Wilhelm Aleksieva was born on 2 November 1944 in Sofia. She graduated from the National art academy “N. Pavlovich”, Sofia, Department of Monumental-decorative painting, with Prof. Gocho Bogdanov. She worked in the field of painting, tapestry, monumental murals and illustration, makes stamps, tapestries, animated films. The paintings she created are few in number, but today have become iconic and are the property of Sofia City Art Gallery and other collections. Since 1974 she has participated in a number of general art exhibitions in Bulgaria and abroad, in which she shows a vivid development and affinity for the urban theme and its modern, photorealistic transformation.
She became known for the original covers she created between 1979 and 1989 for the books in the science fiction series Galactica Library of the Publishing House from Varna Georgi Bakalov. In addition to the series of covers for Galactica Library, Tekla Aleksieva has contributed to science fiction in Bulgaria by participating in initiatives of the Science fiction clubs in Bulgaria and the Club of the Bulgarian fiction artists "Vassil Ivanov" – exhibitions of science fiction art.
In the 1980s, Tekla Aleksieva also illustrated the covers of the Eco series and the library Bulgaria, she also worked on the design of textbooks, the experimental textbook of 1980, the book of “Kibea” Publishing House “Spiritual Guides of Bulgaria” (in collaboration with artist Boyan Filchev and Hristo Hadzhitanev), calendars and more. In 1996, Tekla Aleksieva implemented a postage stamp project with the image of Baba Marta, which, according to critics, is the first attempt to convey her mythological, rather than folklore, image.
She has won awards at illustration exhibitions in Bulgaria, and in 1985 on Bulgarian National Television was screened a film about her with screenwriter and host Stefan Tihchev.
Although she has an incredible popularity and presence in the media environment in Bulgaria and a number of fans, Tekla Aleksieva has no solo exhibitions in representative galleries and museums in Bulgaria and abroad until 2019. In 2016, she had an exhibition in the space of her friends Artie Jamboure in Sofia. “The Galaxies of Tekla” exhibition at SARIEV Gallery, Plovdiv in 2019 is the first analytical presentation of her work.
She is a member of the Union of Bulgarian Artists.