Complex sentence: The arms were borne by the unrelated families of Warbelton, from Cheshire, and Gorges, from Somerset, apparently without knowledge of each other, until John de Warbelton and Theobald de Gorges served together in the English army at the Siege of Calais in 1346/7.
Split into simpler sentences: The arms were borne by the unrelated families of Warbelton, from Cheshire, and Gorges, from Somerset, apparently without knowledge of their common usage. The matter however became apparent when John de Warbelton and Theobald de Gorges were both serving together in the English army at the Siege of Calais in 1346/7.