[3][4][5][6] He first became known as a portrait painter but later turned his brush to genre art, often featuring pretty young girls (see first painting); his work became very popular.

[8] The Victoria and Albert Museum possesses his oil painting Granville Sharp the Abolitionist Rescuing a Slave from the Hands of His Master[9] Hayllar's work was also used for advertising purposes.

[11][12][13] It is interesting to note that Hayllar could sometimes receive rather mixed criticism, as shown in The Atheneum's report on the entries in the 1861 exhibition of the RBA.

Similarly, but superior in solidity, is The Opera Box (50), study of a lady's head in an opera cloak-pretty but common.These trifles are ever snares for facile painters like Mr Hayllar; we regret to see the number of these he produces, remembering better things by him.The local press could be more positive, particularly where a full-sized painting is described, as shown by the Reading Mercury's reasonably accurate description of The first born at the cottage in 1881.

This the mother, a cottager, is showing with maternal pride to two young ladies, while a child, who accompanies them, in her eagerness to nurse it, has dropped some flowers on the floor.

They lived at a house called "Castle Priory"[18] in Wallingford on the River Thames in Berkshire (now Oxfordshire) from 1875–99; scenes from village life in the area often featured in his work there.