Complex sentence: Sharpe was managing the project largely from Paris, through a series of agents, but by the latter part of 1864 the stress was adversely affecting his health, so in 1865 he spent some time in Italy to recuperate.
Split into simpler sentences: Sharpe was managing the project largely from Paris, through a series of agents. By the latter part of 1864 the stress was adversely affecting his health, so in 1865 he spent some time in Italy to recuperate.