Complex sentence: Joachim Cronman was the son of Hans Detterman Cronman (1590--c1645), war commissar (kriegskommissär) of the Swedish Army and Lord of Alatskivi in Swedish Livonia.
Split into simpler sentences: Joachim Cronman was the son of Hans Detterman Cronman (1590--c1645). Hans as the war commissar (kriegskommissär) of the Swedish Army and Lord of Alatskivi in Swedish Livonia.