Complex sentence: He later entered the household of Archbishop Theobald of Bec of Canterbury (d.1163), a near-contemporary of Thomas Becket and John of Salisbury, who also served the archbishop in the 1150s.
Split into simpler sentences: He later entered the household of Archbishop Theobald of Bec of Canterbury (d.1163). He served in the archbishop's household with near-contemporaries Thomas Becket and John of Salisbury in the 1150s.