Complex sentence: Thus, when Greece went to war in the Greco-Turkish War in 1897, the Hellenic Navy established its dominance in the Aegean Sea, however, it was unable to change the outcome of the war on land, which was a national humiliation.
Split into simpler sentences: Thus, when Greece went to war in the Greco-Turkish War in 1897, the Hellenic Navy established its dominance in the Aegean Sea. However, it was unable to change the outcome of the war on land, which was a national humiliation.