In Ireland, as in Britain, disloyalty was usually defined negatively by legal prescriptions for treason, which first received statutory definition in 1352 as the commission of treasonable acts against the king rather than the state or the government. This mediaeval statute applied in Ireland as sister kingdom under the same monarch. Treason has been described as the Janus face of allegiance, sovereignty and identity. Yet in eighteenth-century Ireland such conceptual polarities were problematic as the loyalties they represented were shifting, making Proteus a better metaphor for the resultant complexities. This situation had historical roots: the Protestant Reformation's failure ensured that the native populace and some ‘Old English’ aristocrats remained Catholic, yet technically owed allegiance to a Protestant monarch as head of the established church. The seventeenth-century plantations further complicated matters and introduced more ambiguities. Influxes of English and Scottish Protestants were followed by an Irish Catholic rising and the extension of the war between Charles I and parliament. During this period aristocratic Catholics of both Anglo-Norman and native Irish ancestry fought as loyalists for the king, while many of the Scottish settlers in Ulster supported parliament and branded their opponents rebels. Already inclined towards the non-hierarchical Presbyterianism form of church government, and uneasy within the established Church of Ireland, when the English parliament sent General Munroe's Scottish army to Ireland, the settlers seized the opportunity to organise the first presbytery in 1642 and spread the Solemn League and Covenant.