One of the many unique characteristics of IPA is its fascinating and often debated history. The storied past of India Pale Ale began over 175 years ago, in England. To understand how and why the IPA was first brewed for export, one must understand the hop and the rest will make perfect sense. Hops comprise of two major acids providing a preservative in addition to taste bitterness. The combination of a high hopping rate and high alcohol content allowed for this new style of beer to survive the long journey and not kill anyone who drank it once it got there.
The most commonly recounted story of IPA involves one George Hodgson of the Bow Brewery who was the go-to guy for the beer needs of the East India Trading Company, which supplied brew for the imperial troops stationed in what was known at the time as British India. The first recorded mention of Hodgson's Pale Ale in India was in 1801 and it's unlikely that his was the first. It is important to understand that IPA was not instantly created and named India Pale Ale, but rather an evolution based on the popularity of the style 'abroad' and sought after, years later back in England. In 1822 Samuel Allsopp of Burton Brewers was asked to brew an "India Ale" by the East India Trading Company, reportedly perfecting the style and becoming the premier brewer of IPA.
As for the tale of a shipwreck laden with IPA which washed ashore and started a domestic infatuation with the style, we can't confirm or deny its validity. Lots of ships sunk during those times so we are not going to rule out one massive impromptu IPA party, it's just too fun to imagine it. It is safe to say that back then as now, people demanded more of the flavorful brew and it became more popular as a result.
You wouldn't think war would have much of an impact on a particular beer style, but the First World War did just that. Great Britain enacted several cost prohibitive measures including a levy on any beer over 1055 OG which limited alcohol levels and a brewing tax hike levied in 1900. Land used for growing barley and hops was needed for food and the IPA had effectively become a standard strength Pale Ale.
Today of course, the IPA is on an unstoppable course as it rides the wave of the worldwide craft beer movement and has become such a phenomenon that well, it has its own website ;)