Sergijus Baublys was born in Lida in 1912. He was the fifth of six sons in the family of educator Petras Baublys. He graduated from the Aušra Boys' Gymnasium in Kaunas, was an active Scout and received his higher education in Czechoslovakia. After returning to Lithuania, from 1937 he taught at vocational schools in Kaišiadorys and later Alytus. Sergijus was a specialist in engineering drawing and an educator.

During the Second World War, Sergijus and his wife Jadvyga lived on the outskirts of Kaunas. They were raising their young son Petriukas, while Jadvyga was expecting their second child. Jadvyga's younger sister Marytė and Sergijus's parents also lived with them. Although their two-bedroom apartment was already crowded, the Baublys family took in ten-year-old Jewish girl Rachilė Bliumental.

Before the war Rachilė lived in Kaunas and attended the private Jewish Švabė school. Her parents were divorced; her father worked as an electrician and owned his own business. Rachilė's parents had a close Lithuanian friend, Valčiūnas, who knew one of the six Baublys brothers. Through this connection the girl was entrusted to the younger brother, Sergijus.

A new identity was created for Rachilė. She was to call herself Lena Vorobjova and say that she was a Russian girl whose Lithuanian mother had gone to Russia and married a Russian man. Rachilė recalled that at first only Sergijus and his parents knew her true identity.

As the front approached Kaunas, remaining at home became increasingly dangerous. On Jadvyga's initiative, the family and Rachilė left for Bružė village near Vilkija, where they stayed with a miller's family. From there they saw smoke rising in the direction of Kaunas. Soon a villager returning from the city reported that the ghetto was burning: its liquidation had begun.

Rachilė survived the Holocaust. Her mother Esia Sandler was deported to the Stutthof concentration camp and died there of typhus on 18 January 1945. Rachilė's father survived. In 1957 Rachilė left for Poland and, after receiving documents, went to Geneva to join her father. Because she knew German, she later worked as an analyst and translator.

Sergijus's concern for others did not end with the war. He helped the orphan Mykolas Mankevičius, whose parents had been murdered by the Nazis in the Vilnius region, to pursue an education, and he supported other people in need.

After the war Sergijus continued his work as an educator. From 1944 to 1947 he was deputy director of Kaunas Polytechnic. In 1947 he left to head the Vilnius State Technical School and later returned to Kaunas. From 1951 to 1955 he served as director of Kaunas Polytechnic and continued teaching technical drawing there until 1973.

In the recollections of former colleagues and students, Sergijus appears not only as a specialist but also as an educator who brought young people together. He cared about the learning environment and teaching materials, technical creativity, sports and artistic activities. Sergijus and Jadvyga raised three sons—Petras, Leonardas and Gediminas; their middle son Leonardas later graduated from Kaunas Polytechnic himself.

Sergijus Baublys died in 1976. In 1977 Yad Vashem recognized Sergijus Baublys and his wife Jadvyga as Righteous Among the Nations. Sergijus did not live to see the recognition. The awards were accepted and memorial trees were planted in Israel by his brother Rostislovas (Rostis) Baublys, an architect and bibliophile who lived in Great Britain.

Their granddaughter Rytė Baublytė recounts that Sergijus studied bus body design in Czechoslovakia. She remembers him as a deeply humane man with exceptional personal integrity and a remarkable instinct for teaching. He did not use physical punishment with his grandchildren; Rytė does not even remember him raising his voice sharply. He taught the children to draw, assembled model ships from tiny plastic parts with his grandson Laimonas, and picked berries in the garden with his grandchildren.

Sergijus drew beautifully and was a skilled woodworker. During the Soviet period, he built a small wooden garden house himself, where his three grandchildren spent their summers. The grandparents’ garden was carefully maintained, and Sergijus and his sons built a rock garden from stones. According to Rytė, the plot received an award for its beautifully maintained grounds.

Rytė also remembers her grandfather’s efforts to give all three grandchildren equal attention and an equal share of treats. Even the strawberries he brought back from the garden were divided so that a grandchild who was absent that day would receive a share.

Their granddaughter Rytė Baublytė recalls that the family told the children about Rachilė’s rescue once they were old enough to understand the story. Her grandparents kept a copy of the book “Ir be ginklo kariai” (“Warriors Without Weapons”). After finding an account of physician Petras Baublys and her own grandparents in it, Rytė asked her grandmother what had happened.

According to Rytė, Rachilė and her father remained in contact with the Baublys family. Until her death, Rachilė would occasionally telephone them and send New Year greetings. During the Soviet period, the family received beautiful wall calendars every year from Switzerland, where Rachilė lived after the war. Rachilė and her father also provided Jadvyga with financial support, although she never asked them for it.

A story that Rytė recorded from her grandmother shows how the Baublys family cared for the children amid wartime shortages. When Rachilė was already living in their home, their son Petras was three years old. One morning, there was only one egg for breakfast. Jadvyga wondered aloud what to do: there were two children, but only one egg. Sergijus suggested dividing it in half and giving a share to each child.