The Quartet on the Middle East, sometimes called the Diplomatic Quartet or Madrid Quartet or simply the Quartet, is a foursome of nations and international and supranational entities involved in mediating the peace process in the Israeli-Palestinian conflict. The Quartet are the United Nations, the United States, the European Union, and Russia. The group was established in Madrid in 2002, recalling Madrid Conference of 1991, as a result of the escalating conflict in the Middle East. Tony Blair is the Quartet's current Special Envoy.

The initiative to establish the Quartet evolved following the outbreak of the Second Intifada in September 2000 and the futile cease-fire attempts that followed. On October 25, 2001, representatives of the EU, UN and the US and Russian governments met Palestinian leader Yasser Arafat and jointly expressed support for his policy of implementing cease-fire and security reforms in the Palestinian Authority. During the Israeli incursions into Palestinian areas in April 2002, the representatives of the same four entities met in Madrid and again called for implementation of cease-fire agreements brokered by the US government before. In the same meeting, they also agreed to transform their quadripartite cooperation into a permanent forum for follow-up of the Israeli-Palestinian peace process.

Dustin Lee Hoffman (born August 8, 1937) is an American actor with a career in film, television, and theatre since 1960. He has been known for his versatile portrayals of antiheroes and vulnerable characters.

He first drew critical praise for the play Eh?, for which he won a Theatre World Award and a Drama Desk Award. This was soon followed by his breakthrough movie role as the good-looking but troubled Benjamin Braddock in The Graduate (1967). Since then Hoffman's career has largely been focused on cinema, with only sporadic returns to television and the stage. Some of his most notable films are Papillon, Marathon Man, Midnight Cowboy, Little Big Man, Lenny, All the President's Men, Kramer vs. Kramer, Tootsie, Rain Man, Wag the Dog, and Meet the Fockers.

Hoffman has won two Academy Awards (for his performances in Kramer vs. Kramer and Rain Man), five Golden Globes, four BAFTAs, three Drama Desk Awards, a Genie Award, and an Emmy Award. Dustin Hoffman received the AFI Life Achievement Award in 1999.

Anna Yuryevna Netrebko (Russian: Анна Юрьевна Нетребко, born 18 September 1971) is a Russian operatic soprano. She now holds dual Russian and Austrian citizenship and currently resides in Vienna. She has been nicknamed "La Bellissima" by fans.

Netrebko was born in Krasnodar (Russia), in a family of Kuban Cossack background. While a student at the Saint Petersburg conservatoire, Netrebko worked as a janitor at Saint Petersburg's Mariinsky Theatre. Later, she auditioned for the Mariinsky Theatre, where conductor Valery Gergiev recognized her from her prior work in the theater. He subsequently became her vocal mentor. Under Gergiev's guidance, Netrebko made her operatic stage debut at the Mariinsky at age 22, as Susanna in Le nozze di Figaro. She went on to sing many prominent roles with the Kirov Opera, including Amina in La sonnambula, Pamina in Die Zauberflöte, Rosina in Il Barbiere di Siviglia, and Lucia in Lucia di Lammermoor.

In 1994, she sang the Queen of the Night in Die Zauberflöte with the Riga Independent Opera Avangarda Akadēmija under conductor David Milnes.

Dame Margaret Natalie "Maggie" Smith, DBE (born 28 December 1934) is an English film, stage and television actress. She has had an extensive career both on screen and in live theatre, and is known as one of Britain's pre-eminent actors. She made her stage debut in 1952 and is still performing after 60 years. She has won numerous awards for acting, both for the stage and for film, including seven BAFTA Awards (five competitive awards and two special awards including the Bafta Fellowship in 1996), two Academy Awards, two Golden Globes, two Emmy Awards, a Laurence Olivier Award, two SAG Awards and a Tony Award. Dame Maggie is the only actor ever to win this collective of awards and is one of the most successful and acclaimed actors of the film era.

Her critically acclaimed films include Othello (1965), The Prime of Miss Jean Brodie (1969), Travels with My Aunt (1972), California Suite (1978), Clash of the Titans (1981), A Room with a View (1985) and Gosford Park (2001). She has also appeared in a number of widely-popular films, including Hook (1991), Sister Act (1992) and as Professor Minerva McGonagall in the Harry Potter film series. She currently stars in the critically acclaimed drama Downton Abbey as Violet Crawley, the Dowager Countess of Grantham, for which she has won an Emmy.

Oscar Emmanuel Peterson CC CQ OOnt (August 15, 1925 – December 23, 2007) was a Canadian jazz pianist and composer. He was called the "Maharaja of the keyboard" by Duke Ellington, "O.P." by his friends. He released over 200 recordings, won eight Grammy Awards, and received other numerous awards and honours over the course of his career. He is considered to have been one of the greatest jazz pianists of all time, having played thousands of live concerts to audiences worldwide in a career lasting more than 60 years.

Peterson was born to immigrants from the West Indies; his father worked as a porter for Canadian Pacific Railway. Peterson grew up in the neighbourhood of Little Burgundy in Montreal, Quebec. It was in this predominantly black neighbourhood that he found himself surrounded by the jazz culture that flourished in the early 20th century. At the age of five, Peterson began honing his skills with the trumpet and piano. However, a bout of tuberculosis at age seven prevented him from playing the trumpet again, and so he directed all his attention to the piano. His father, Daniel Peterson, an amateur trumpeter and pianist, was one of his first music teachers, and his sister Daisy taught young Oscar classical piano. Young Oscar was persistent at practising scales and classical etudes daily, and thanks to such arduous practice he developed his astonishing virtuosity.