Breanski originally came from Greenwich but he specialised in painting Welsh and Scottish landscapes, in particular highland lochs at sunset. In later life he also painted a number of views of the Thames, including a picture of Windsor Castle.

He was a meticulous painter, who almost always recorded the exact location of his paintings with an inscription on the reverse of the canvas and occasionally, the day's date. From 1869 he was a frequent exhibitor at the Royal Academy London, the Royal Society of British Artists Suffolk Street and the New Watercolour Society. His work was highly acclaimed and much sought after. His paintings feature in the collections of several museums and public art galleries around the world. The Sydney Museum in Australia holds 'A Welsh Road - The Village Inn'. His two sons Gustave and Alfred Fontville were both painters, but their work was not of the same quality as Alfred's.