The Invisible College, Mapped

In 1977 Oscar Schachter described the people who practise, teach and judge international law as an "invisible college".1O. Schachter, 'The Invisible College of International Lawyers' (1977) 72 Northwestern University Law Review 217. He had first used the phrase in 1973, in a piece for the centenary of the Institut de Droit International. The phrase has stuck because it describes something members of the profession recognise but rarely write down: a small, mobile community whose members move between the academy, the Foreign Office, the Bar, arbitral tribunals and the international bench, and who carry ideas with them as they go. The standard account of the sources of international law leaves little room for them. States make the law, by treaty and by custom, and the writings of jurists are at most evidence of what states have done.

Obituaries give a different picture, written by the profession about itself. The British Yearbook of International Law has printed obituaries of international lawyers since its first volume in 1920, which opened with a notice of Lassa Oppenheim, one of its founders.2E. A. Whittuck, 'Professor Oppenheim' (1920) 1 BYIL 1. Oppenheim died in 1919, before the first volume appeared. Between 1920 and 2017 the Yearbook published 58 of them. They name mentors and pupils, predecessors and successors, co-counsel and co-arbitrators, friends and the occasional rival. They also acknowledge, more openly than academic writing usually does, that individuals shaped the law. Michael Wood's encyclopaedia entry on the teachings of publicists keeps writers to the role of promoting a better understanding of the law. His obituary of Ian Sinclair credits Sinclair with "a significant role in the recognition" of the commercial exception to state immunity.3Compare M. Wood, 'Teachings of the Most Highly Qualified Publicists', Max Planck Encyclopedia of Public International Law (2010), with F. Berman and M. Wood, 'Sir Ian Sinclair, KCMG, QC (1926–2013)' (2013) 83 BYIL 1.

We read every obituary, logged every person it named and every relationship it described, and drew the result as a network of 180 people and 226 ties. The plates below show that network, with portraits where one exists, together with the lives, birthplaces and offices behind it. The dataset is partial by design: the Yearbook is a national journal, so the college it remembers is a British one, and an obituary describes the profession as it was when its subject was active. We have tried to read the material with those limits in view.

Hover over a face to see that person's ties, and click to hold them. The layout is the one from the original analysis, in which people who share connections are drawn together and the best connected settle near the middle. Lord McNair is at the centre because his own obituary and those of his pupils mention him repeatedly: he taught Hersch Lauterpacht, Robert Jennings and Gerald Fitzmaurice, Lauterpacht followed him into the Whewell Chair and then on to the International Court, and Humphrey Waldock followed him at Strasbourg.4Size is degree, the number of recorded ties. Faces appear where a portrait could be found; the rest are plain discs. The dashed chips highlight the holders of one office in turn.

In some cases international law ran in the family. Lord Phillimore, the British member of the committee that drafted the Statute of the Permanent Court, was the son of a judge of the Admiralty Court, which at the time heard most of the English cases with an international element. Édouard Rolin-Jaequemyns, "born in the purple" in Wilfred Jenks's phrase, was present as a child at the founding of the Institut de Droit International in his father's house in Ghent, and later followed his father as editor of the Revue and member of the Institut.5C. W. Jenks, 'Baron Édouard Rolin Jaequemyns' (1937) 18 BYIL 156; J. Fischer Williams, 'Lord Phillimore' (1929) 10 BYIL 197.

The professional lineages are longer and better documented, because an obituary almost always says whose pupil its subject was and who took over the chair or the seat. McNair taught at the London School of Economics, revised Oppenheim's treatise, held the Whewell Chair at Cambridge, became the first British judge of the International Court and then the first President of the European Court of Human Rights. Lauterpacht, who became his closest friend in the difficult years after arriving from Vienna, followed him at the LSE, in the Whewell Chair and at The Hague, and moved his family into McNair's former house in Cambridge.6R. Y. Jennings, 'Hersch Lauterpacht: A Personal Recollection' (1997) 8 EJIL 301. Jennings, another McNair pupil, wrote that it was "quite right to couple a recollection of Hersch Lauterpacht with Arnold McNair". Lauterpacht's seat at the Court passed to Fitzmaurice, another McNair pupil. Fitzmaurice and Waldock then swapped: Waldock took the Hague seat and Fitzmaurice the Strasbourg one, and Waldock also finished Fitzmaurice's work on the law of treaties at the International Law Commission. Jennings held the Whewell Chair for twenty-one years, went to the Court when Waldock died, and was followed there by his own pupil, Rosalyn Higgins. Jennings's chair went to Derek Bowett, whose career ran in parallel with Ian Brownlie's: rival theses on the use of force, opposite sides in case after case, and the rival chairs at Cambridge and Oxford. James Crawford was Brownlie's doctoral student at Oxford and held the Whewell Chair for another twenty-one years before going to the Court himself.

Plate II lays five of these successions out in order. The obituaries supply the links between the people; the tenures come from the published lists of office-holders, and where an office-holder never appears in the Yearbook the frame is left empty.

The Yearbook runs from 1920 to 2017, with a break during the Second World War. The lives it records extend well beyond those dates in both directions. The oldest people in the network were born in the 1820s, and the most recent are still alive, because an obituary names the living alongside the dead: the pupil who wrote it, the colleague who was mentioned, the successor who took the chair. Plate III draws every life for which Wikidata gives dates, ordered by year of birth, with the subjects of obituaries marked in gold and the women in white.7Dates come from Wikidata, matched to the names in the dataset. The matching was automatic and then checked by hand; a handful of minor figures have no entry and are left out of this plate.

Fourteen of the 58 subjects were not British. The early volumes were the most open: Édouard Clunet in 1923, Ernest Nys and Francis Hagerup in 1921, Walther Schücking and Albrecht Mendelssohn Bartholdy in 1937. Only four of the fourteen were born outside Europe, and two of those four, Elihu Root and Manley Hudson, were American; the others were D. P. O'Connell, an Australian, and Sakuyé Takahashi.8The non-British subjects are listed at n 125 of the article. Oppenheim and Lauterpacht count among them: both were born abroad and made their careers in England. International law has a long history of contributions from the Global South, and even a list as selective as this one is notable for the names it lacks. Alejandro Álvarez, Christopher Weeramantry and Eduardo Jiménez de Aréchaga are absent from the Yearbook's obituaries, as are Felice Morgenstern and Suzanne Bastid.

The most common tie in the network is the obituary itself: who wrote about whom. The rest records the informal side of the profession, which rosters, judgments and citation counts leave out. Colleagues at Cambridge or at the Foreign Office, editors and co-authors of the Yearbook and the treatises, mentors and pupils, co-counsel and co-arbitrators, successors in a chair or a seat, friends, rivals and kin. Two of the strongest ties in the map join people who disagreed: McNair and Lauterpacht on the law of treaties, Bowett and Brownlie on the use of force. A network shows where ideas travelled, and says nothing about whether they were accepted.

Schachter's lasting point was that the same people move between roles, and that the moving is how a sense of justice gets written into the law without any state consenting to it. The obituaries bear him out. Of the 180 people, 105 held an academic post at some point, 66 practised at the Bar, 48 advised a government, 47 sat on a bench of some kind and 37 arbitrated. Nearly half held two or more of these roles. Filtering the fuller attributes in the original dataset, thirty people were both academics and barristers, fifteen were Foreign Office advisers who also practised, and Roberto Ago, Gerald Fitzmaurice and Humphrey Waldock sat on both the International Law Commission and the International Court.9The role counts in the chord diagram are computed from the six role families in the published dataset. The filter results are those reported at nn 122–124 of the article, which drew on finer-grained attributes.

Whose life is memorialised says something about how a group works. In ninety-seven years the Yearbook devoted an obituary to two women. Joyce Gutteridge, the first woman appointed Assistant Legal Adviser at the Foreign Office, was remembered in 1992 by Francis Vallat, who wrote that had she been a man she would have received the CMG rather than the CBE. Gillian White, the first woman to hold a chair in law in mainland Britain, was remembered in 2017 by Iain Scobbie, Jean d'Aspremont and Yenkong Ngangjoh Hodu.10F. Vallat, 'Miss Joyce Gutteridge, CBE (1906–1992)' (1992) 63 BYIL xiv; I. Scobbie, J. d'Aspremont and Y. Ngangjoh Hodu, 'Professor Gillian White (1936–2016)' (2017) 86 BYIL 1. Two women wrote obituaries: Rosalyn Higgins on Robert Jennings, and Felice Morgenstern, with two others, on Wilfred Jenks. A few more are mentioned as pupils, research assistants or colleagues. The remaining women in the obituaries are widows, former wives and daughters.

White's position in the network is also telling. She has one of the higher degrees in it, and her ties run mostly to other women and to colleagues at Manchester, so she sits away from the centre, which is occupied by men who combined academic work with practice. Education points the same way: filter the map by Oxford or Cambridge with the chip on Plate I, and most of it stays lit.

The absences matter as much as the entries. Five people whose standing in the discipline would have earned a notice in most other journals have none here.

A network built from one journal's obituaries records what that journal chose to remember. It privileges the British experience, it reflects the profession as it stood when its subjects were active rather than as it stands now, and it says nothing about the large law firms and the proliferating tribunals that have reshaped practice since the 1990s. We have not run the centrality and clustering measures a sociologist would run, because the data would not bear them. The method is social network analysis used descriptively, to show insiders what they already half know and outsiders what they rarely see. The article describes the result as reliable but not bulletproof, and the plates should be read on that basis.11The phrase is Isobel Roele's: 'The Making of International Lawyers: Winnicott's Transitional Objects', in J. Hohmann and D. Joyce (eds), International Law's Objects (2018) 72, at 87.

The data were gathered into two spreadsheets. One lists people, with the positions each held, where they were educated and the bodies and journals they belonged to. The other lists ties, each with its source obituary, its target and the kind of relationship the text described, so that a pair who were both colleagues and co-authors appear twice. The layout and the clusters were computed in Gephi for the article and are reproduced here unchanged. Dates, birthplaces and the short descriptions on the cards were added for this essay from Wikipedia and Wikidata, matched by name and then checked. Portraits were gathered from public collections and institutional pages, and the credits below list the source of every image.