National Australia Bank Ltd. (ASX: NAB) is an international financial services organization providing advice, products, and services in Australia, New Zealand, Asia, the United Kingdom and the United States. The majority of NAB's operations are based in Australia with over 60 percent of its clients and employees coming from Australia.  NAB also operates in New Zealand under the Bank of New Zealand brand, in the UK through Clydesdale Bank and Yorkshire Bank brands and in the US under the Great Western brand.
Australia’s banking market is dominated by four major banks of which National Australia Bank Ltd. is the third. The three other banks are Australia and New Zealand Banking Group (ASX: ANZ), Commonwealth Bank of Australia (ASX:CBA) and Westpac Banking (ASX: WBC).
National Australia Bank Ltd. is involved in a variety of financial services but NAB's largest cash earnings have come from business banking ($2,193 million AUD FY2010) where NAB is also the largest competitor with 22.5 percent of business lending market share. Over the 17 months to August 2010, NAB increased business lending by a net $1.9 billion at a time when the industry contracted its lending by an aggregated $40 billion net. 
The Australian government is currently working to reform various parts of its financial services industry. On June 2, 2011 the Australian government announced it would reform the insolvency industry and banks remain nervous that regulation might affect future operations. 
National Australia Bank Ltd. began in 1858 as The National Bank of Australasia with its headquarters in Melbourne. The National Bank of Australasia quickly grew through the years and over the course of the early 20th century absorbed a number of other Australian banks. However, it was only in 1981 when The National Bank of Australasia merged with Commercial Banking Company of Sydney that it came to be known as The National Australia Bank. This merger not only changed the name of NAB but also allowed it to become an active player in international and domestic banking.
Like most banks National Australia Bank Ltd. was adversely affected by the financial crisis of 2008/09, with dividends falling roughly 25 percent from 97 cents in 2008 to 73 cents in 2009. NAB was particularly affected (in comparison to other Australian banks) due to its active involvement in the US and UK banking and real estate sectors. This involvement led to shares falling 13.5 percent on July 24, 2008, which was NAB's biggest drop in 21 years.  However, NAB weathered the storm well and by September 30, 2010 cash earnings increased 19.3 percent to $4.58 billion AUD.
While the 2008 financial crisis was damaging for Australian banks it was much worse for other nations banking systems. As a result all four of Australians 'big four' banks entered into the top 20 global banks for the first time ever . NAB has used its strong performance through the financial crisis to expand operations by purchasing other companies. In 2009 NAB identified wealth management, insurance and its advisory business as key growth areas and acquired Aviva’s Australian division for $825 million to expand its wealth management options. NAB also acquired the mortgage management business of Challenger for $385 million (now known as Advantedge) and 80.1 percent of Goldman Sachs JBwere for $99 million to further expand its wealth management options.
National Australia Bank Ltd. consists of four banking segments which handle their various financial operations in Oceania, the UK, USA, and Asia.
National Australia Bank Ltd’s primary competition are the other three “big four” banks of Australia, but due to its international holdings NAB also competes with large banks in the US and UK. Within Australia NAB's major competitors are: