From an Apollo magazine online article:

Things take an even stranger turn when he gets to Egypt, and his own features still appear again and again; not, as before, as a barely significant detail in an otherwise busy composition, but as a principal element. In a series of fine single-figure paintings brought together at the Watts Gallery, Lewis represents himself as a Syrian sheikh scanning the horizon of the Sinai desert; as the suave ‘bey’ of a Cairene household, lowering his eyelids as his servant offers him a water pipe; as an impassive carpet-seller in the Bezestein bazaar. In none of these, however, does he quite meet our eye.

In his mid thirties, an age at which most ambitious artists were making themselves as visible as possible, John Frederick Lewis (1804–76), a successful painter of sporting subjects and Mediterranean scenes, vanished from London for more than a decade. It was an audacious move. He spent two years in Italy, then followed in Lord Byron’s footsteps, travelling through Albania, Corfu, Athens and Smyrna, and after a year in Constantinople he sailed for Egypt. Once there Lewis fell in love with Cairo, and rather than returning to England with his sketchbooks he set up home, staying until 1851. Those years might have been something of a biographical blank had it not been for a visit in 1844 from his old friend William Makepeace Thackeray, who included a somewhat excitable account in his travel book Notes of a Journey from Cornhill to Grand Cairo (1846). 

To read more: https://www.apollo-magazine.com/john-frederick-lewis-watts-gallery-review/?utm_medium=email&utm_campaign=APWH%20%2020191004%20%20AL&utm_content=APWH%20%2020191004%20%20AL+CID_8f41f662a8c7742f6db2d929c7188b59&utm_source=CampaignMonitor_Apollo&utm_term=Read%20the%20full%20article