Theobald Michau studied with the landscape painter Lucas Achtschellinck in Brussels. He was made Master of the Guild in Brussels in 1698, and was elected a member of the Guild of Antwerp in 1710. The height of Michau's success was marked by the purchase of ten of his works by the Governor of the Low Countries, Charles of Lorraine. Several engravings were made after Michau's works by Jacques-Philippe Lebas and his pupils, and the landscape painter Jacques d'Arthois asked him to paint the figures in some of his landscape compositions.
Michau continued the Flemish landscape and genre tradition of Jan Breughel the Elder and David Teniers the Younger.