Blackface American minstrels were popular in England from the 1850s, but blackface in mummers and morris dancers (see Steve, above) seems to have been well-established earlier- a change in persona if not a disguise.
If any racial connotation was there, it more likely would have to do with the Moors, but impersonation and mime traditions involving them are only documented for European areas formerly governed by the Moors, or for areas such as Mexico-southwestern U. S. where Spanish immigrants settled in the 16th-18th c.