Complex sentence: The new owners changed the name to "The Herald and Advertiser and Commercial Chronicle" in 1803 and to "The Glasgow Herald" in 1805, when Thomas Mennons severed his ties to the paper.
Split into simpler sentences: The new owners changed the name to "The Herald and Advertiser and Commercial Chronicle" in 1803. In 1805 the name changed this time to "The Glasgow Herald" when Thomas Mennons severed his ties to the paper.