William Herschel was descended from one of three brothers, whose Lutheran opinions made it expedient for them to quit Moravia early in the seventeenth century. Hans Herschel thereupon settled as a brewer at Pirna, in Saxony; his son Abraham rose to some repute as a landscape-gardener in the royal service at Dresden; and Abraham's youngest son, Isaac, brought into the world with him, in 1707, an irresistible instinct and aptitude for music. Having studied at Berlin, he made his way in 1731 to Hanover, where he was immediately appointed oboist in the band of the Hanoverian Guard. A year later he married Anna Ilse Moritzen, by whom he had ten children. The fourth of these, Frederick William, known to fame as William Herschel, was born November 15th, 1738.

His brilliant faculties quickly displayed themselves. At the garrison-school he easily distanced his brother Jacob, his senior by four years, and learned besides, privately, whatever French and mathematics the master could teach him. He showed also a pronounced talent for music, and was already, at fourteen, a proficient on the hautboy and violin. In this direction lay his manifest destiny. His father was now bandmaster of the Guard; he was poor, and had no other provision to give his sons than to train them in his own art; and thus William, driven by necessity to become self-supporting while still a boy, entered the band as oboist in 1753.