Complex sentence: The Mac Giolla Phádraig clan became the rulers by the late tenth century; their name was anglicised as Fitzpatrick upon their formal submission to Henry VIII of England in 1537.
Split into simpler sentences: The Mac Giolla Phádraig clan became the rulers by the late tenth century. Their name was later anglicised to FitzPatrick upon their formal submission to King Henry VIII of England in 1537.