Joseph Gregor Werner (bapt. 29 January 1693 Ybbs/Danube Austria,
died 3 March 1766 Eisenstadt, Hungary, now Austria) was musical director at the
court of the Esterházy family from 1728. For 5 years, from
1761 Joseph Haydn was his — not so much esteemed — vice court
musician. The latter, in contrary, published some
introductions and fugues of his predecessor in 1804. Werner
wrote chamber music, symphonies, a-capella masses and
oratories. One of the best known is the "Musicalischer
Instrumental-Calender" (a collection of chamber concerts
published 1748, portraying each month in 4 or 5 allegoric
pieces (signs of the zodiac, length of days and nights,
characteristic labours and entertainments etc.). On 3rd
march 1766 Gregor Joseph Werner died in the princely
residence in Eisenstadt and Haydn became his successor.

(Taken (and translated) from the German text in the Honegger/M. Encyclopedia.)