[1] Cayley was born at Brompton, near Scarborough, North Yorkshire, where his family had lived and held a baronetcy since the 17th century.
His grandfather, the 6th baronet – also named George Cayley (1773–1857) – was among other things an early pioneer of aeronautics.
George Allanson Cayley was educated at Eton and Trinity College, Cambridge.
[2] In 1859 he married his first cousin, Catherine Louisa, daughter of Sir William Worsley, 1st Baronet, of Hovingham, 25 miles from Brompton.
[3] He stood for Parliament in the Ripon constituency in the 1868 general election[4] but was defeated by the sitting MP, Lord John Hay.