Jesse Mattinson and Alex Illsley join Outer Temple Chambers as Pupil Barristers.

Outer Temple Chambers are delighted to have taken on new pupils Jesse Mattinson and Alex Illsley, who commenced their pupillage with us on 1st September 2026.

We are pleased to welcome new pupils Jesse and Alex to our set. We are sure that they will gain excellent experience and thrive during their pupillage at Outer Temple Chambers. Find out more on our new pupils below.

Head of Pupillage

Head of Pupillage, Saul Margo says “We are delighted to welcome Jesse and Alex to Chambers. They overcame stiff competition to obtain pupillage at OTC and we look forward to being part of what is hopefully a successful and enjoyable year ahead.”

Jesse Mattinson

Before commencing pupillage, Jesse worked as a legal assistant at an American law firm specialising in litigation. He assisted on complex commercial matters including an arbitration annulment application and the GDP-linked bonds litigation against the Republic of Argentina. Jesse graduated with First Class Honours in English Law and French Law LLB from King’s College London. As part of his degree, he studied law in French at Paris-Panthéon-Assas University, where he obtained a French Master’s degree in law.

Alex Illsley

Prior to pupillage, Alex worked as a self-employed County Court Advocate, where he appeared in a variety of hearings, including road traffic, credit hire, and landlord and tenant matters. Alex graduated from the University of Oxford with First Class Honours in Jurisprudence, and returned to Oxford, completing the Bachelor of Civil Law and Master of Philosophy postgraduate degrees. Alex went on to complete the Bar Course at City, University of London.

News 1 Sep, 2026