Complex sentence: In Alcácer the Miguelist forces captured some ground, that was quickly lost to General Saldanha in Pernes and Almoster, the latter action, which occurred on February 18,1834, was the most violent and bloody of the Civil War.
Split into simpler sentences: In Alcácer the Miguelist forces captured some ground but this was quickly lost to General Saldanha in Pernes and Almoster. The latter action (February 18,1834) was the most violent and bloody of the civil war.