Complex sentence: The museums history started with the establishment in 2005 with the Encaustic Art Institute founded by Douglas Mehrens, and immediately started collection encaustic art for the sole purpose to have a permanent collection that could become part of a museum.
Split into simpler sentences: The museums history started with the establishment, in 2005, of the Encaustic Art Institute founded by Douglas Mehrens. He immediately started collecting Encaustic art for the sole purpose of having a permanent collection that could become part of a museum.