Complex sentence: In the regional dialect, the local society was called "Watu wa Miti," it was a foundation stone for what became an international organization, the Men of the Trees (a translation of the original name).
Split into simpler sentences: In the regional dialect, the local society was called "Watu wa Miti". This formed the foundation stone for what was to become an international organization, the Men of the Trees (a translation of the original name).