Complex sentence: On 7 August 1986, in protest at the Anglo-Irish Agreement, Northern unionist politician Peter Robinson led an "invasion party" of 500 unionist militants into Clontibret and held a military drill in the square, before retreating back across the border.
Split into simpler sentences: On 7 August 1986, in protest at the Anglo-Irish Agreement, Northern unionist politician Peter Robinson led an "invasion party" of 500 unionist militants into Clontibret. Held a military drill in the square, before retreating back across the border.