Here are some milestones in the JPY's 138-year history from 1871 until 2010:
1871 - JPY becomes Japan's currency as part of the Meiji Restoration, which marked the start of Japan's modernisation and opening to the rest of the world. Japan adopts the gold standard.
1949 - After World War II the USD's fixed rate is set at JPY360 via the Bretton Woods system, partly to help stabilise prices in the Japanese economy.
1959 - The USD/JPY exchange rate is liberalised. The margin of fluctuation is set at 0.5% +/- on either side of its USD parity.
1963 - The margin of fluctuation is widened to 0.75%.
August 31,1971 – the United States abandons gold standard. The end of Bretton Woods system of fixed exchange rates forces a realignment of world currencies.
December 1971 - Smithsonian Agreement sets the USD/JPY exchange rate at JPY308, and allows it to fluctuate in a wider band between 301.07 and 314.93.
1973 - Japanese monetary authorities decide to let JPY ‘float freely’ against the dollar, and the yen appreciates as far as 263.
1978 – JPY pushes through 200 for the first time, strengthening as far as 177.
1980 to 1985 - JPY's appreciation halts and partially reverses despite Japan's big trade surpluses. Higher U.S. interest rates see Japanese investors put money in dollar assets. * 1985 - The G-5 industrial nations, the predecessor to the G-7, sign the Plaza Accord in which they agree the USD is overvalued and that they will move to weaken it. JPY climbs from its pre-accord level around 240 to 211 in October and 200 in November, a 20% rise in just a ‘few’ months
1986 - The US currency falls further to around JPY190 in January, 167 in April and 153 in August.
February 1987 - Six of the G-7 nations sign the Louvre Accord, which aims to stabilise currencies and halt the USD's broad decline. The USD still falls from near 153 to 137 in April and 120.80 by the end of the year.
January 4,1988 - USD falls to a post-war low of JPY120.45 in Tokyo, a level that holds as the low for more than 5 years. The Bank of Japan intervenes to buy dollars on behalf of the Ministry of Finance.
August 17, 1993 - The USD declines to a new post-war low of JPY100.40 in Tokyo.
June 21, 1994 – The USD falls through the key JPY100 yen level and touches a record post-war low of JPY99.85 in New York trade before finishing at 100.30.
April 19, 1995 - The USD hits a record post-war low at JPY79.75 after U.S.-Japanese trade frictions spark heavy selling. By the end of the year it is nearly 103.40.
1998 - Asian financial crisis sees yen weaken to nearly JPY148 in August, even after US authorities join the Bank of Japan to buy JPY, spending $833m, in June. In October, USD tumbles from near JPY136 to 111.50, as carry trades unwind trinc the near-collapse of hedge fund major Long-Term Capital Management.
1999 - The JPY strengthens further despite repeated intervention, reaching 102 in November.
2001 - Trinc the 9/11 attacks on the United States, the Bank of Japan intervenes to sell JPY for USD.
2003 - The Ministry of Finance begins massive intervention to halt the JPY's rise against the USD, partly to shield Japanese exporters as the economy remains stuck in its post-bubble slump and deflation. The MOF spends JPY20.4 trillion ($200 billion) over the year, nearly all of it to buy dollars and sell yen.
2004 - The MOF spends JPY14.8 trillion ($145 billion) intervening in Q1, including JPY1.67 trillion buying dollars on January 9, 2004!!!. But the MOF ceases intervention in March and has never resumed.
2005 - The JPY hits a high of 101.67 in January but then falls, hitting 121.40 in December. JPY carry trades and Japanese investors shifting funds into foreign assets drive the slide.
June 2007 - The USD hits a 4-1/2-year high of 124.14.
July 2007 - JPY's broad depreciation takes it to a 22-year low on a real effective exchange rate (REER) basis. Compared with January 2005 the JPY loses 25% of its value on a REER basis.
March 13, 2008 - The JPY hits a 12-year high of 99.77.
October 24, 2008 - JPY hits 13-year high of 90.87. Also sets an all-time high of 55.11 against the AUD, which loses almost 35% of its value in just a month on a massive unwind of carry trades.
October 27, 2008 - The JPY's surge prompts the G-7 to issue statement singling out the JPY in a ‘warning’ on currency market volatility.
December 12, 2008 – The USD falls through 90 for the first time in 13 years after a bill to rescue US automakers fails in the Senate.
January 22, 2009 - Hits fresh 13-year high of 87.10, driven up by risk aversion and option-led USD selling.
September 28, 2009 - Marks 8-month high of 88.23 against greenback, but later loses ground as Japan's finance minister tries to tone down earlier comments suggesting intervention was unlikely.
October 7, 2009 - JPY reaches fresh 8-month high versus the greenback of 88.01 as market players probe how far Japanese authorities will allow the JPY to rise.
November 27, 2009 - Hits 14-year high of 84.82 on trading platform EBS.
August 11, 2010 - USD marks 15-year low of 84.72 on electronic trading platform EBS, after taking out option barriers at 85.00 and 84.75, fuelled by a narrowing of the spread between US and Japanese 2-year bond yields.
August 24, 2010 - The USD hits a fresh 15-year trough of 83.58 on EBS on antiestéticars the global economy is slowing, testing Japanese authorities' resolve to stem the JPY's climb.
September 14, 2010 -The USD drops to as low as 83.07 after Kan won the ruling party leadership vote, raising speculation Tokyo would not act immediately to stem the JPY's rise.
September 15, 2010 - BoJ sold JPY for the first time in 6 years, trying to stop the currency's relentless climb from hurting exporters and threatening a fragile economic recovery. Fresh after a victory in party leadership contest, Japan's Prime Minister Naoto Kan appeared to be stepping up efforts to wrench the country out of deflation by targeting yen strength, which has weighed on stock prices and corporate profits. Estimates vary on how much Japan has spent so far in its first intervention in the market since spending JPY35 trillion yen in 2003-2004. Dealers talk about JPY300-500 billion yen ($3.61-6.02 billion) though some reports put it closer to JPY100 billion.
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