Complex sentence: In 1999, he was appointed a Knight of the Order of the Garter, and served as colonel of the Irish Guards between 2000 and 2008; additionally, he was appointed Lord Steward of the Royal Household in 2001.
Split into simpler sentences: In 1999, he was appointed a Knight of the Order of the Garter, and was colonel of the Irish Guards from 2000 to 2008. Additionally, he was appointed Lord Steward of the Royal Household in 2001.