Accustomed as many historians are to diminishing the impact of the individual on the broader process of historical change, the course of the Parnell split appears to defy expectations. The actions of a single individual of tremendous prestige and influence shattered a political consensus carefully established over a decade of intense political organisation and party discipline. The home rule party was centrally controlled and disciplined to an extent unique to late nineteenth-century British politics. Parnell was the undisputed leader of the party and, for many, the primary cause of its political success: he appeared to be indispensable. For F. S. L. Lyons, Parnell's most important modern biographer, the split was the final act of a tragic life. With ‘the Chief’ exposed as an adulterer and rejected by Gladstone because he was afraid ballasting Parnell would alienate his party's core nonconformist constituency, the majority of Parnell's parliamentary colleagues eschewed him in favour of the Liberal alliance. Parnell's personal animus overrode the strategic necessity of preserving the ‘union of hearts’, an action Conor Cruise O'Brien finds ‘indefensible’. A later generation of historians have viewed the split as a catalyst, facilitating the establishment of a fresh Parnellite dynamic along non-sectarian lines, as intimated in the late 1880s. Frank Callanan is aggressively Parnell's advocate, intent upon discerning a political strategy that would restore independence to the home rule party and free Irish nationalism of its endemic Catholic ‘supremacism’.