(covers information from several alternate timelines)
After the USS Franklin crash landed on Altamid in 2164, its captain, Balthazar Edison, and two surviving members of the crew found a drone workforce and ships from a previous civilization. Using this technology, Edison, who renamed himself "Krall", built a base where he could held prisoners taken from ships he captured. There, he used energy transference on them to prolong him, Kalara's, and Manas' life for the next 100 years.
In 2263 of the alternate reality, Krall took the crew of USS Enterprise to his base, where he held them as his prisoners to continue prolonging his and Manas' life and to find the last piece of the Abronath.(Star Trek Beyond)