Question: International Consolidated Airlines Group, S.A., often shortened to IAG, is an Anglo-Spanish multinational airline holding company,  it was formed in January of which year, after a merger agreement between British Airways and Iberia, the flag carrier airlines of the United Kingdom and Spain respectively?

Context paragraphs:
Aer Lingus: Aer Lingus, ( , an anglicisation of the Irish "aerloingeas" meaning "air fleet") is the flag carrier airline of Ireland and the second-largest airline in Ireland.  Founded by the Irish government, it was privatised between 2006 and 2015 and it is now a wholly owned subsidiary of International Airlines Group (IAG), the parent company of British Airways and Iberia.  The airline's head office is on the grounds of Dublin Airport in Cloghran, County Dublin, Ireland.

Iberia (airline): Iberia ( ), legally incorporated as "Iberia, Líneas Aéreas de España, S.A. Operadora, Sociedad Unipersonal", is the flag carrier airline of Spain founded in 1927.  Based in Madrid, it operates an international network of services from its main base of Madrid-Barajas Airport.

Martin Broughton: Sir Martin Faulkner Broughton (born 15 April 1947) is a British businessman and Deputy Chairman of International Airlines Group.  Formed in January 2011, IAG is the parent company of British Airways, Iberia and Vueling.  It is a Spanish registered company with shares traded on the London Stock Exchange and Spanish Stock Exchanges.  The corporate head office for IAG is in London, UK. .  He is also a managing partner at Sports Investment Partners.  He is a former chairman of Liverpool Football Club and also served as President of the Confederation of British Industry.

International Airlines Group: International Consolidated Airlines Group, S.A., often shortened to IAG, is an Anglo-Spanish multinational airline holding company with its operational headquarters in London, England and its registered office in Madrid, Spain.  It was formed in January 2011 after a merger agreement between British Airways and Iberia, the flag carrier airlines of the United Kingdom and Spain respectively.  As British Airways was the larger company, those holding shares in British Airways at the time of the merger were given 55% of the shares in the new, merged company.  British Airways and Iberia ceased to be independent companies and instead became 100% owned subsidiaries of IAG.  It is the sixth-largest airline company in the world, producing €22.567 billion revenue in 2016.  The company is listed on the London Stock Exchange and the Madrid Stock Exchange.  It is a constituent of the FTSE 100 Index and IBEX 35 Index.

China Airlines: China Airlines (CAL) () () is the flag carrier and largest airline of the Republic of China (Taiwan).  It is headquartered in Taoyuan International Airport and has 12,607 regular employees.  China Airlines operates over 1,400 flights weekly to 118 airports in 115 cities (including codeshare) across Asia, Europe, North America and Oceania.  The cargo division operates 91 pure freighter flights weekly.  The carrier was, in 2013, the 29th and 10th largest airline in the world in terms of passenger revenue per kilometer (RPK) and freight RPK, respectively.  China Airlines has three airline subsidiaries: Mandarin Airlines operates flights to domestic and low-demand regional destinations; China Airlines Cargo, a member of Skyteam Cargo, operates a fleet of freighter aircraft and manages its parent airline's cargo-hold capacity; Tigerair Taiwan is a low-cost carrier established by China Airlines and Singaporean airline group Tigerair Holdings and is wholly owned by China Airlines Group.

United Continental Holdings: United Continental Holdings, Inc. (formerly UAL Corporation) is a publicly traded airline holding company headquartered in the Willis Tower in Chicago.  UCH owns and operates United Airlines, Inc.  The company is the successor of UAL Corporation, which agreed to change its name to United Continental Holdings in May 2010, when a merger agreement was reached between United and Continental Airlines.  Its stock trades under the UAL symbol.  To effect the merger, Continental shareholders received 1.05 shares of UAL stock for each Continental share, effectively meaning Continental was acquired by UAL Corporation; at the time of closing, it was estimated that United shareholders owned 55% of the merged entity and Continental shareholders owned 45%.  The company or its subsidiary airlines also have several other subsidiaries.  Once completely combined, United became the world's largest airline, as measured by revenue passenger miles. United is a founding member of the Star Alliance.

British Airways: British Airways (BA) is the largest airline in the United Kingdom based on fleet size, or the second largest, behind easyJet, when measured by passengers carried.  The airline is based in Waterside near its main hub at London Heathrow Airport.  In January 2011 BA merged with Iberia, creating the International Airlines Group (IAG), a holding company registered in Madrid, Spain.  IAG is the world's third-largest airline group in terms of annual revenue and the second-largest in Europe.  It is listed on the London Stock Exchange and in the FTSE 100 Index.

Air Nicaragua: Nicaragua Airways is the potential future national flag carrier of Nicaragua.  Its main base is Augusto C. Sandino International Airport, Managua.  It is the first time in 20 years that Nicaragua will have a national flag carrier, after Aeronica ceased operations in 1991.  Since then, the flag carrier status was awarded to Nicaragüense de Aviación also known as NICA Airlines.  Several airlines had tried to become the Nicaraguan flag carrier like CAAL (Central American Airlines), SANSA (Servicios Aereos Nicaraguenses S.A.) but none of these survived a year.  Today even NICA Airlines (6Y) is registered as the national airline of Nicaragua, the only international flight it operated once (Managua to Miami) and is done under the TACA code (TA) as a full TACA Airlines flight.

American Airlines Group: American Airlines Group, Inc. is an American publicly traded airline holding company headquartered in Fort Worth, Texas.  It was formed December 9, 2013, in the merger of AMR Corporation, the parent company of American Airlines, and US Airways Group, the parent company of US Airways.  The airline groups together form the largest airline in the world, with more than 6,700 daily flights to 336 locations in 56 countries worldwide, about $40 billion in operating revenue, over 100,000 employees, and plans to take delivery of 607 new aircraft, including 517 narrowbody aircraft and 90 widebody international aircraft.  The integration of American Airlines and US Airways was completed when the Federal Aviation Administration granted a single operating certificate for both carriers on April 8, 2015.

Level (airline): Level is a low-cost travel brand based at Barcelona–El Prat Airport in Spain.  It is a wholly owned subsidiary of the multinational airline holding company International Airlines Group (IAG) that operates under an independent brand name.  Level is marketed as a low-cost long-haul carrier, and began operations in June 2017 with service from Barcelona to Los Angeles, Oakland, Buenos Aires and Punta Cana.

Supporting paragraphs: International Airlines Group Iberia (airline)
Answer: 2011