Abstract: The Magna Carta Lawful Rebellion [MCLR] is an example of a “legal cult,” a social group organized around key guru leaders who obtain their elevated status and hold followers via alleged special knowledge of law. The MCLR’s two gurus, David Robinson and Jacquie Phoenix (legal name Jacqueline Robinson), claimed the true binding law for residents of the Commonwealth is a hidden secret law, called “pseudolaw.” Pseudolaw is a highly conserved set of false legal concepts nested in a conspiratorial narrative. Pseudolaw originated in the US, but post2000 has spread world-wide. The MCLR pseudolaw variant is that the 1215 Magna Carta remains in effect and operates as a supraconstitutional authority. Robinson and Phoenix claim that individuals may defeat conventional legal and state authority by swearing an oath of allegiance to Lord Craigmyle of Invernesshire, a “New Rebel Baron.” Special paperwork then permits extraordinary authority, including the right to execute government authorities and other enemies. However, MCLR adherents instead employed these concepts in petty domestic circumstances, and without any success. The MCLR’s leadership and adherent population appear similar: low-income, uneducated, and marginal persons with conspiratorial anti-authority beliefs. This “cult of peers” largely operates online. The MCLR was a minor and comparatively unsuccessful branch of UK pseudolaw culture until 2019, when Phoenix attracted numerous followers, and led a “Redress” movement that promised defeat of New World Order oppressors via execution of “traitors and quislings.” The 2021 failure of the “Redress” effort now threatens Phoenix’s status, and the long-term viability of the MCLR and its concepts.