A half-length portrait to right in captain's (over three years) undress uniform, 1748-67, and wearing his own hair. His sword hangs from a cloth baldric. The lapels of the coat do not resemble the original pattern and have been altered for fashion. His sword appears on the right. The sitter meets the gaze of the viewer and the portrait is remarkable for the emphasis Hogarth has placed on facial characteristics and origin.

Schomberg was the son of Meyer Löw Schomberg, a German-Jewish doctor who settled in England about 1720. There were several brothers, one being the physician Ralph Schomberg, whose portrait by Gainsborough is in the National Portrait Gallery; another, Isaac, was also a physician and a friend of Hogarth. Alexander joined the navy in 1743, became a captain in 1757 and after an active and laudable career was knighted in 1777. He commanded the 'Diana', 32 guns, at the taking of Louisbourg in 1758, where he played a distinguished part. In 1759, still in the 'Diana', he assisted at the taking of Quebec and was closely associated with Wolfe. He later commanded the 'Essex' and at the peace of 1763 he married Arabella Susanna Chalmers. This portrait may have been commissioned and completed in time for the wedding. He had other commands but in 1771 he became captain of the 'Dorset', the Lord-Lieutenant of Ireland's yacht, in spite of the opposition of Lord Sandwich, First Lord of the Admiralty. He held this position for over 30 years, until 1804, and for a great many of them was at the top of the captain's list, since the captain of a royal yacht who wished to remain in command was not promoted to a flag rank. The portrait is signed and dated, 1763.