Allen &amp; OveryAllen &amp; Overy Allen & Overy Allen & Overy LLP (informally A&O) is an international law firm. It is a member of the UK's Magic Circle of leading law firms. In 2019, Allen & Overy advised on more transactional deals than any other law firm in the world and was one of two firms to have surpassed the US$1 trillion mark in terms of deal value, totalling US$1.16 trillion. As of 2019, Allen & Overy is the world's 10th largest law firm by revenue. History. Allen & Overy was founded in the City of London on 1 January 1930 by George Allen and Thomas  Overy, formerly partners at Roney & Co. The main purpose was to build a commercial practice. The firm's reputation was made as a result of George Allen's role as adviser to King Edward VIII during the abdication crisis of 1936. By the time World War II broke out in 1939, Allen & Overy had firmly established itself as a leading City law firm. Over the years, Allen & Overy has been involved in many developments in the legal field. Such work has included advising on the first hostile takeover in the City of London and acting for S. G. Warburg & Co.  The firm arranged the first Eurobond (issued by Italian motorway group Autostrada) in the 1960s. The Eurobond transaction significantly diversified Allen & Overy's practice from a purely commercial into commercial and financial firm. Through the 1970s the firm's finance and corporate practice grew in the UK and internationally. In 1996, non-UK clients contributed more to Allen & Overy's revenue than UK clients. In 1998, non-UK clients contributed two-thirds of revenue. In 1999, Allen & Overy hired a team of banking and finance lawyers in Paris from its then ally, Gide Loyrette Nouel. In 2000, Allen & Overy merged  with part of the Amsterdam, Brussels and Luxembourg offices of Loeff Claeys Verbeke. In May 2004, the worldwide partnership of Allen & Overy converted to a limited liability partnership, Allen & Overy LLP, which works together with associated undertakings in some jurisdictions to form a worldwide legal practice. In July 2008 Allen & Overy broke the £1 billion turnover mark, and, for the first time, over half of its turnover was generated outside London. In 2009, following the Global Financial Crisis, Allen & Overy completed a redundancy programme which saw 400 partners and staff lose their jobs globally. As well as cutting 47  partners, the firm cut around 200 fee-earners and 200 members of support staff, half of which were based in London. Allen & Overy de-equitised a further 35 partners. In the same year, Allen & Overy demerged its private client department, which became Maurice Turnor Gardner LLP. In 2014, Allen & Overy became the first Magic Circle firm to establish an office in sub-Saharan Africa when it opened an office in Johannesburg, South Africa. A 2021 assessment singled out Allen & Overy among law firms as engaging in the most transactional work for fossil fuel companies. Offices. Allen & Overy has 44 offices  in 31 countries across Africa, Asia Pacific, Europe, North America, Latin America and the Middle East. Diversity and inclusion. In 2018, the firm has faced criticism over diversity and gender pay gap Leadership. The table below sets out a history of Allen & Overy's leadership: Notable alumni. Some of the firm's notable alumni include: Allen & Overy Allen & Overy LLP (informally A&O) is an international law firm. It is a member of the UK's Magic Circle of leading law firms. In 2019, Allen & Overy advised on more transactional deals than any other law firm in the world and was