[3] He was apprenticed to the artist Copley Fielding, where he learnt the technique of plein air sketching.

[5] After exhibiting a watercolour of Richmond Hill in the Paris Salon of 1831, he was offered a job teaching the family of King Louis Philippe I of France, and for several years gave lessons to the Duc de Nemours and Princess Clémentine,[3] while his own works rapidly gained popularity in England.

Briefly the 'Callow youth' was plunged into a platonic love affair that went unrequited with the darling Princess Clementine.

[6] Elected a member of the Old Water-Colour Society, Callow returned to London in 1841 and began to paint larger pictures, moving away from the more "dashing" style of his earlier smaller works.

[7] He travelled extensively in France, the Netherlands, Belgium, Germany, Switzerland and Italy,[8] had a large number of pupils, and enjoyed favour with the royal family.