Three predictions made by this theory were :
The first effect was actually known before 1915, but there was no explanation until Einstein's theory.
Many texts will tell you that the second effect was observed at a total solar eclipse that occurred in 1919. However, the average bending of stellar light passing close to the Sun was actually closer to Newston's prediction of the effect (half that predicted by GR). It was not until the Wallal total solar eclipse in Australia in 1922 that there was truly convincing evidence that Einstein's value was correct.
Again, although there was a claim for gravitational redshift (time dilation effect) being observed in 1925, instruments sensitive enough to observe this effect were not available until 1954.
The final prediction of General Relativity to be confirmed directly by experiment was that of the existence of Gravitational Waves in 2015 (although indirect evidence for GW was made in 1974 by Joe Taylor and Russell Hulse in their observation of period decline in a binary star system - for which they were awarded a Nobel Prize).
The first direct detection, 100 years after Einstein's Annus Mirabilis (Miracle Year) was made on 14 Sept 2015 by the two LIGO observatories (one at Hanford, Washington, NW USA) and the other at Livingston in Louisiana). Both observatories used incredibly sensitive interferometers to measure fractional changes in the north-south and east-west arm lengths (~ 4km long) of 10-22.
The event that produced the first detection was caused by two black holes spiralling around each other until they finally coalesced. These masses were appoximately 1.4 billion light years from Earth and produced a total energy output equivalent to the mass of 3 Suns by their merger.
The event lasted a total of 200 milliseconds. It was designated GW150914.