Complex sentence: It has been speculated that the red hand here is the hand of the O'Neill family since the Battle of Clontibret between the forces of Hugh O'Neill and the English Crown was fought in northern Monaghan in May 1595.
Split into simpler sentences: It has been speculated that the red hand here is the hand of the O'Neill family since the Battle of Clontibret. The Battle of Clontibret between the forces of Hugh O'Neill, The O'Neill, and the English Crown was fought in northern Monaghan in May 1595.