Childhood: he was born to a moderately wealthy family. His father died in a duel when David was 9 and he sent off to live with his well-off architect uncle. He went to school where he received poor grades and always painted hiding from the teachers. He tried to win the prestigious 3 times and failed Prix de Rome (which would let him go to Rome to study art) many times, when once, he got so mad he starved in protest. The fourth time, he won and went to Rome. :D . 

Painter Jacques-Louis David was a dictator of the arts under the French Republic and a great supporter of the French Revolution.  He was also a good buddy of Roberspierre (the guy who reigned with terror, many people were executed...he  also advocated abolish of slavery, human rights and universal male suffrage... also talked a lot about how execution without trial of the enemies of the Republic is virtuous... until he was guillotined himself.). After Roberspierre was executed, Louis David was sent to prison and after he got released (mostly due to his wife) he needed to align himself with the new power - Napoleon Bonaparte. He knew Napoleon through a mutual friend - Josephine, whom Napoleon later married. Josephine was a widow of Alexandre de Beauharnais, who was a noble killed by the revolutionaries... David signed the paper that would make the revolutionaries kill Alexandre. 

Napoleon was named emperor with huge support from the french society. Napoleon made a lavish ceremony where he was crowned in a mix of the old ancient traditions and republican traditions. He wanted to make sure that he was an emperor with republican ideals and did not "descend" from any old power which were overthrown by the French Revolution. The number of onlookers for the procession of the coronation is estimated at 4-5 thousand people. The procession was led by a bishop on a mule. An huge air balloon, shining with three thousand lights in a pattern of the imperial crown was let off in front of the Notre Dame Cathedral where the coronation was held. Multiple orchestras and choruses were playing for the occasion. 

The pope blessed the imperial couple and then wanted to crown Napoleon, when the crown held by the pope was almost on his head, Napoleon took it out of the pope's hands, crowned himself and crowned his wife Josephine. Afterwards Napoleon swore an oath to the Bible to protect freedom of religion, equality of rights, not to raise taxes for no reason and other things.

Napoleon commissioned Jacques-Louis David to depict the coronation in all it's splendor and glory and, to also deliver some important political messages. The Pope was present in the ceremony, yet he was not the one giving crown to Napoleon, just blessing him. In the first sketch, Napoleon was depicted crowning himself to show his independence from the Church. In the final version Napoleon is shown to be crowning his wife Josephine (perhaps to show a less authoritarian version of himself, more of a chivalrous knight that an authoritarian dictator) . The painter himself was present in the ceremony and is also depicted among the crowd. At first, he was invited to the ceremony but Napoleon wanted to make him sit far away from the action, the painter got so angry that he started a fight. His arrogant personality and his role in the Terror made him many enemies. However, he was still regarded as the leading painter in Western Europe of the time. 

Jacques-Louis David painted in the ceremony and also got people to pose for him in his studio afterwards. He also, upon Napoleon's request, painted in some people who weren't present at the ceremony. The painting was very realistic and life like, the only big change the painter has made was to make the scale of Notre Dame cathedral smaller so that the people and the ceremony looked more important and grand. 

Napoleons brother Joseph Bonaparte is depicted, though he wasn't even invited to the coronation because of a disagreement between the siblings. Napoleon's mother is depicted in a more important place than the pope, but in reality she did not even attend the wedding in protestation to their son's recent quarrel. All of his siblings are depicted. Talleyrand was present, an Ottoman ambassador Halet Efendi is depicted and many other important figures of the time are seen there.