The following is an extract from the Inaugural Lecture of Professor Vaughan Lowe, former Chichele Professor of Public International Law and Fellow of All Souls College

The teaching of international law at Oxford in fact dates from a time long before the foundation of the Chichele Chair in 1859 . Though it is the Regius Professor of Civil Law in Oxford who has succeeded to the mantle of Alberico Gentili, who was appointed as Regius Professor here in 1587, the international lawyers claim the intellectual inheritance.

Gentili was among the first of the many refugees who have, over the centuries, found safety and welcome in England, and who, perhaps learning by painful experience the value of the Rule of Law, have made major contributions to the development of International Law.

His name and work are less well known today than that of Grotius; but Gentili is in many respects the greater and the more modern of the two. It is Gentili who is the happier arguing on the basis of reason and common sense, rather than Greek or Roman precedents; who discusses contemporary State practice. In this, and in his preference for discussing the particular, concrete case, rather than setting out broad generalisations, he took an approach that bears many similarities to that adopted by those who followed him in Oxford.

So too does his involvement in public affairs. Gentili was consulted by the English Government in the case of Bernardino de Mendoza, the Spanish ambassador accused, on the basis of a confession drawn from Francis Throckmorton on the rack, of complicity in the plot to depose Elizabeth I and put Mary Queen of Scots upon the throne. Gentili – like his successors four hundred years later when faced with a comparable question after the shooting of PC Yvonne Fletcher from the Libyan Embassy in London – advised that it was right to expel the ambassador from England rather than to try him and to punish him here.

The work of Gentili was continued by his successor but one, Richard Zouche, now sadly neglected, but plainly deserving his place in the Pantheon of international lawyers. It was Zouche who first shifted the title of the subject to inter national law – Jus inter Gentes , instead of the Jus Gentium – Law of Nations – of his predecessors, and who produced what has been called the first manual of the positive Law of Nations – that is, the first text based primarily upon principles derived from the customary practices of States, rather than from natural law and the natural order of things.

The Chichele Chair in international law and diplomacy was founded two centuries after Zouche, in 1859, out of the revenues of All Souls College. The first holder was Mountague Bernard. Bernard's family, like Gentili's, were protestant refugees; and for generations the Bernard family owned land at Montego Bay in Jamaica, the place of the signing of the 1982 Law of the Sea Convention, on which a subsequent Chichele Professor, Dan O'Connell, wrote one of his many scholarly texts. Such are the curiosities of everyday life.

Bernard's career combined scholarship with professional practice and public service. He is now remembered chiefly for his role in presenting the British defence to the case brought against it by the United States in the Alabama claims arbitration ; but he also deserves to be remembered, this year at least, as Secretary of the Royal Commission established in 1868 to investigate the cattle plague that had killed around 400,000 cattle in Britain in the mid-1860s.

Bernard was succeeded in 1874 by Sir Thomas Erskine Holland, the first great scholar to hold the chair. It was Holland's inaugural lecture that restored the reputation of Gentili to its proper place, and began a link between Oxford and San Ginesio, Gentili's birthplace in Northern Italy, that is – happily – active to this very day.

Holland, too, played his part in public life. He was, for instance, author of the Royal Navy's Manual of Naval Prize Law . That link, too, has been restored. The Navy now sends its lawyers to study in Oxford before they go off to postings, where they may carry responsibility for interpreting and applying the law of armed conflict and other branches of international law. Holland also served on the British delegation to the Geneva Conference that drafted the great Geneva Conventions of 1907 on the Laws of War, which I mentioned earlier as descendants of the Deuteronomic code.

It was Holland who was said by a later Oxford lawyer to have made his main contribution to scholarship in the form of letters to The Times . That is not entirely fair to the co-founder of the Law Quarterly Review , author of a text on jurisprudence that ran to many editions, and editor of the works of Gentili, Zouche, and an earlier Italian writer on international law, Legnano; nor is the sneer deserved. Holland's letters were almost certainly much more widely read than any other writing on international law at that time; and they ran to three editions when they were reprinted in hardback. Nonetheless, he has paid the penalty that Academe often exacts from those who strive to make their subject intelligible to laymen.

Holland was succeeded in 1911 by Sir Erle Richards, who had been counsel for the United Kingdom in various arbitrations in the early part of the twentieth century; and Richards was followed in turn, in 1922, by James Brierly, perhaps the first of the holders of the Chichele Chair to have established a firm reputation as a distinguished and original scholar in the field of international law. His incisive essays marked him out as a man whose precise and subtle analyses never wandered from the bedrock of pragmatism and realism; and those qualities were well deployed when Brierly was appointed as one of the original members of the International Law Commission in 1948.

At that point we move within the reach of living memory; and with the customary discretion I shall say only that during the past half century the chair has been held by three very distinguished international lawyers, whose reputations and influence in the world of legal practice stand as high as their reputations as legal scholars: Sir Humphrey Waldock, sometime President of the International Court of Justice; and Dan O'Connell and Ian Brownlie, both of them authors of outstanding textbooks on the subject, among their many other scholarly writings.

The continuous involvement of all these international lawyers in public service and in the practice of international law ensured that the law that they taught was not confined to a recitation of the established classic cases, but was illuminated by the immediacy and directness of their involvement with international law as it operates in the real world.