Green’s Dictionary of Slang

Old Harry n.

[give old Harry is still current in W.I. use; Nares, Glossary (1822), defines the phr. as ‘formerly applied satirically to Henry the Eighth’]

1. [mid-17C+] (also Lord Harry, old Henry) the Devil.

2. [late 17C–early 19C] a form of unspecified adulterant used in wine.

In phrases

like old Harry (adv.)

[mid-19C; 1970s] to a great (lit. ‘devilish’) extent.

play old Harry (with) (v.) (also give old Harry)

[19C–1900s] to ‘play the Devil’ (with), to make mischief, to tease or scold.