Complex sentence: The most important were (socage tenure) and military service (Knight-service), the performance of some form of religious service (frankalmoigne tenure) and personal/official service, including in times of war (serjeanty tenure).
Split into simpler sentences: The most important were (socage tenure) and military service (Knight-service). Other examples include Knight-service (frankalmoigne tenure) and personal/official service (serjeanty tenure).