Chapter I (Introduction) starts with an orientation on problems caused by the co-existence of a confusing number of Orders of St. John, all basing their lineage on the original Order, formed around 1050, which would never have ended. The much energy consuming issue of recognised versus false Orders of St. John seems mainly caused because Alliance Orders donot allow other organisations of St. John to connect on equal footing to the charitable conceptof St. John, as developed since the late 19th century, harking back to the romanticised idealistic starting phase in the 11th century, when Amalfi merchants founded the originalOrder of St. John. The issues appear to be not purely academic, because in various countrieslaw suits were and are being conducted about them. Chapter I then goes into the subject of the study more closely, i.e. how to determine whenan Order of St. John has a legitimate character. In this context, a number of observations isnecessarily devoted to the important, but difficult subject of legitimacy. Hereafter, a number of questions of an historical-legal nature are formulated and a status quaestionis is provided. The issues appear to have been studied more or less by various authors, but not always systematically, while also more than once polemic treatment seems to occur. For these reasons, but also and mainly out of pure scientific curiosity, the authordeemed it necessary to prepare this study. It is hoped it will be regarded as an objectivecontribution and a responsible attempt to a more scientific debate, as well as a helping hand to those who, in whatsoever capacity, might be called upon to determine the legitimacy of anOrder of St. John. The method used is historical/critical-legal, as well as inductive, in which context an Order, qualified by many as an important false Order of St. John, was selected as departure point. Chapters II (A critical look at the historical developments) through VIII (Sixth phase (1940-2004): several Orders disputing each other's legitimacy; the creation of The International Alliance of Orders Of St. John), contain a critical historical/legal analysis of developments inthe history of the original Order, respectively of the phenomenon of Orders of St. John,deemed of importance for this study. This history is subdivided into six more or less traditional phases. In this context, connected to the above indicated historical developments in each phase, various remarks are made and knowledge and insight are gained, which are ofimportance for the later responding to the research questions put in Chapter I. Chapter IX (Chivalric definitions) discusses some definitions of a chivalric Order which weredeveloped in the literature. Attention is also drawn to some international developments inthis context. Also some case-law and legislation is discussed. Chapter X (The organisation of the original Order) sketches the main lines of theorganisation of the original Order, i.e. the Order of St. John founded around 1050 and whichin the author's view at any rate ended in the late 18th century. In Chapters XI (Discussion of some important contemporary Orders of St. John) throughXV (The Sovereign Military Order of Malta), a number of leading contemporary Orders of St. 2 John, i.e. the most important Alliance Orders and their statutes and by-laws, are discussed in the light of the previous chapters and the knowledge and insights gained there. In Chapter XVI (The legal nature and organisation of The Ecumenical Order), the legalnature and organisation of the above indicated socalled false specimen-Order of St. John and its statutes and by-laws, are discussed. In Chapter XVII (The specificity of an Order of St. John), the specificity (the own nature ofan Order of St. John), is discussed, also in the light of a comparison of Orders of St. John with some important service organisations, such as Rotary and Lions and with the important spiritual movement of Freemasonry. Chapter XVIII (Some competition law aspects) contains some remarks about variouscompetition law aspects, connected to actions in the framework of the phenomenon Ordersof St. John and also summarily discusses some case law. On the basis of the foregoing, Chapter XIX (Development of legitimacy criteria andresponding to questions), discusses a number of criteria put forward in the literature and onthat basis, three categories of legitimacy criteria are found, with which one might try todetermine the legitimacy of recognised as well as false Orders of St. John. In Chapter XX (Conclusions), the questions raised are answered as much as possible and anumber of specific and supplemental general conclusions from the research, are laid down.The outcome of the research appears to be of interest, not only to the specimen Orderselected, but also to other Orders of St. John and also otherwise. Sofar, the meaning of the notion 'legitimacy' with regard to the 'historical self-image' of the various Orders of St. John, was never really systematically charted. This led to a bigconfusion of tongues. By legal-historical analysis and by using The Ecumenical Order as a case study, tools are provided to enable critical testing of the criteria applied by various Orders of St. John with regard to their legitimacy claims and to pierce possible myth building. Through this, the author hopes to have developed an instrument which may be ofuse to researchers and others to better determine the legal-historical aspects and legitimacy claims of these para-religious 'chivalric Orders' and similar associations, such as Freemasonry, so that testing, inter alia to operative law in The Netherlands and elsewhere, is better enabled. At any rate it is useful to clearly state the author wanted to deal primarily with the legal aspects of this much more encompassing 19th and 20th century cultural phenomenon.