Among Protestants in Northern Ireland, especially Presbyterians, there is a stronger tradition of individual clerics involved in politics than among Catholics. The tradition is traced over the last hundred years by Andrew Boyd in his Holy War in Belfast and is represented today by, for example, Ian Paisley and the Reverend Martin Smyth, head of the Orange Order, vice president of the Unionist Party and an important factor in the "loyalist" opposition to the White Paper. The three major Protestant groups are the Church of Ireland, which is in communion with the Church of England, the Presbyterians and the Methodists.