SS Titanic (or rather RMS, because it carried the Royal Mail), with its sister ships Olympic and Britannic, was one of the largest transatlantic passenger ships on the White Star Line.
Built by Harland and Wolff in Belfast, she was considered unsinkable in the people's government. But this myth was created by the press and not by the owners (who, however, made no effort to deny the claim), and was due to the fact that the lining was able to stay upright even with four watertight compartments completely flooded. Unfortunately, the number of compartments breached on the night she hit the iceberg was six.
She sank on her first voyage on the night of April 14, 1912. The tragedy, in which 1,503 of the 2,200 passengers on board lost their lives (40% of first class and 70% of third-class passengers), caused a huge outcry and led to the very first conference dedicated to maritime safety.
The Titanic disaster is considered one of the worst peacetime maritime tragedies in history and is by far the most famous.