Complex sentence: The 1st Battalion was posted to India 1919 while the 2nd Battalion was sent to Queenstown in Ireland where it saw saw action during the Irish War of Independence: the battalion was engaged in several fire-fights with the Irish Republican Army.
Split into simpler sentences: The 1st Battalion was posted to India 1919 while the 2nd Battalion was sent to Queenstown in Ireland where it saw saw action during the Irish War of Independence. The regiment was engaged in several fire-fights with the Irish Republican Army.