The traditional date of the beginning of the Seven Years’ War is 1754, when somebody named George Washington attacked a French scouting party, provoking the French into retaliating by attacking and eventually taking over Fort Necessity, Washington’s campout, and destroying it. Washington and his forces would appeal to Great Britain for help, but upon a refusal from the King and his advisors, took matters into their own hands to defend the Ohio Valley, a piece of land that they perceived to be their territory. The French, of course, thought it was their territory as well, and the Seven Years’ War began.
This would not be Washington’s only attempt at conquering non-Thirteen Colonies territory, whether it be in or out of British hands. However, Washington’s attack was but a build-up of long-standing tensions between the French and the British. Britain claimed most of the territory in and around present-day Georgia was theirs, notably due to the Carolina Charter and the Virginia Charter, two charters delimiting what was British land. The French, however, due to the exploits of La Salle and other explorers, claimed that the very same land, up to and including all the territory south towards Louisiana, was theirs. The issue might have remained stagnate for many years unless the French had not massacred English traders that were on “French” (British?) land and destroyed their trading post.
The British colony of Virginia, which happened to be Washington’s home colony, had a political interest in claiming the Ohio Valley, as it had already granted settlement rights in parts of the area to their people. They had based their settlement rights on their founding charter, contesting the validity of La Salle’s journey, because it was many years—a half of a century, even—after the charter was made. In response to the massacre done by the French, Washington eventually took cover at Fort Necessity, biding his time in order to retaliate against French hostilities. In late May of 1754, Washington would indeed retaliate.
American historians will often call the purely colonial side of this war the “French and Indian War”, while calling the larger conflict that would involve fighting in mainland Europe the Seven Years’ Year. Most other English-speaking historians will call the entirety of the conflict, both on colonial and European lands, the Seven Years’ War. Take a French-Canadian history course, as most people will do in Quebec today, and you will hear the war called the conquête, which, if the name doesn’t make it obvious already, will be made clear in the following weeks.