Robert de Lacy was a notable figure in medieval England, known for his role as a landowner and military leader. He was part of the Lacy family, a prominent noble lineage that held significant estates and influence during the 12th century. His contributions to the Norman Conquest helped shape the political landscape of the time. De Lacy is often associated with the establishment of various castles, which served both as fortifications and symbols of power. His legacy includes the development of local governance and the promotion of feudalism in the regions he controlled, impacting the lives of many in medieval society.