Complex sentence: During the 1950s, Roberts was, together with Cledwyn Hughes and others, a stalwart of the Parliament for Wales campaign, and he presented the final petition to Parliament, bearing more than 250,000 signatures, in May 1956.
Split into simpler sentences: During the 1950s, Roberts was, together with Cledwyn Hughes and others, a stalwart of the Parliament for Wales campaign. Eventually, he presented the final petition to Parliament, bearing more than 250,000 signatures, in May 1956.