Complex sentence: The battle took place at the banks of the river Mazā Jugla and one of the main units involved were 6000 Latvian rifleman from the 2nd Latvian Rifleman brigade under the command of Ansis Lielgalvis.
Split into simpler sentences: The battle took place at the banks of the river Mazā Jugla. One of the main units involved was a brigade of 6,000 Latvian Riflemen from the 2nd Latvian Rifles under the command of Ansis Lielgalvis.