Caroline Lucretia Herschel was born in the town of Hanover on 16 March 1750. She was the eighth child and fourth daughter of Isaac Herschel, a self-taught oboist, and his wife, Anna Ilse Moritzen. Isaac became a bandmaster in the Hanoverian Foot Guards, whom he first joined in 1731, and was away with his regiment for substantial periods. He became ill after the Battle of Dettingen (part of the War of the Austrian Succession) in 1743 and never recovered fully; he suffered a weak constitution, chronic pain, and asthma for the remainder of his life. The oldest of their daughters, Sophia, was sixteen years older, and the only surviving girl besides Caroline. She married when Caroline was five, meaning that the younger girl was tasked with much of the household drudgery. Caroline and the other children received a cursory education, learning to read and write and little more. Her father attempted to educate her at home, but his efforts were mostly successful with the boys.
At the age of ten, Caroline was struck with typhus, which stunted her growth, such that she never grew taller than 4 feet 3 inches (1.30 m). She suffered vision loss in her left eye as a result of her illness. Her family assumed that she would never marry and her mother felt it was best for her to train to be a house servant rather than becoming educated in accordance with her father's wishes. Her father sometimes took advantage of her mother's absence by tutoring her individually, or including her in her brother's lessons, such as violin. Caroline was briefly allowed to learn dress-making. Though she learned to do needlework from a neighbour, her efforts were stymied by long hours of household chores. To prevent her from becoming a governess and earning her independence that way, she was forbidden to learn French or more advanced needlework than what she could pick up from neighbours.
Following her father's death, her brothers William and Alexander proposed that she join them in Bath, England to have a trial period as a singer for musician brother William's church performances. Caroline eventually left Hanover on 16 August 1772 after her brother's intervention with their recalcitrant mother. On the journey to England, she was first introduced to astronomy by way of the constellations and opticians' shops.
In Bath, she took on the responsibilities of running William's household, and began learning to sing. William had established himself as an organist and music teacher at 19 New King Street, Bath (now the Herschel Museum of Astronomy). He was also the choirmaster of the Octagon Chapel. William was busy with his musical career and became fairly busy organising public concerts.
Caroline did not blend in with the local society and made few friends, but was finally able to indulge her desire to learn, and took regular singing, English, and arithmetic lessons from her brother, and dance lessons from a local teacher. She also learned to play the harpsichord, and eventually became an integral part in William's musical performances at small gatherings. She became the principal singer at his oratorio concerts, and acquired such a reputation as a vocalist that she was offered an engagement for the Birmingham festival after a performance of Handel's Messiah in April 1778, where she was the first soloist. She declined to sing for any conductor but William, and after that performance, her career as a singer began to decline. Caroline was subsequently replaced as a performer by distinguished soloists from outside the area because William wished to spend less time in rehearsals to focus on astronomy.