Complex sentence: On his return to Spain in 1815, Captain Van Halen's activities during the Spanish War of Independence were investigated and he was imprisoned on 21 March 1817, first in Murcia, and later in Madrid, because of his connections with a Masonic Lodge in Granada.
Split into simpler sentences: On his return to Spain in 1815, Captain Van Halen's activities during the Spanish War of Independence were investigated. He was imprisoned on 21 March 1817, first in Murcia, and later in Madrid, because of his connections with a Masonic Lodge in Granada.