Short answers, pulled from the story.
Hendrik Lorentz shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect, the splitting of spectral lines by magnetic fields. The Royal Swedish Academy cited their "extraordinary service" in researching the influence of magnetism on radiation phenomena.
The Lorentz transformations are a set of equations describing how space and time coordinates change between reference frames moving relative to each other. Lorentz published the complete set in 1904, and Henri Poincare gave them their name in 1905.
Einstein drew heavily on Lorentz's concepts and mathematical results when writing his 1905 paper on special relativity. Lorentz acknowledged that Einstein had achieved what he himself had not: equations that take exactly the same form in moving frames as in stationary ones, by postulating the relativity principle rather than deriving it from electromagnetic equations.
From 1918 to 1926, Lorentz chaired a Dutch government committee tasked with calculating the effects of the proposed Afsluitdijk flood control dam on water levels in the Waddenzee. He solved the problem using hydrodynamic equations of motion solved numerically. When the dam was completed in 1932, his predictions proved remarkably accurate, and one of its two sets of locks was named after him.
Lorentz retained a belief in an undetectable aether in which resting clocks would show the "true time," but acknowledged in 1910 that if the relativity principle held universally, the two pictures yield identical results and the choice between them could be left to the individual.
Lorentz died on the 4th of February 1928 and was buried on the 10th of February in Haarlem. At noon, the State telegraph and telephone services of the Netherlands were suspended for three minutes as a tribute. Albert Einstein, Marie Curie, and Ernest Rutherford, representing the Royal Society, attended the ceremony.