Ignace Pleyel (1757-1831) was a French composer. He became Joseph Haydn's pupil and composed 70 string quartets etc. His name is famous as a founder of Pleyel et Cie, a French piano manufacturing company. He also established a music notes publisher, Maison Pleyel, which published works by Joseph Haydn, Ludwig van Beethoven, Johann Hummel, etc.
Please visit International Ignaz Joseph Pleyel Society (IPG) site for more information.