William I de Ros , MP, Lord of Helmsley, Sir
William I de was born about 1196 in Helmsley Castle, North Ride Yorkshire, England.  He died in 1264 in Poitou, France.

 Lucy FitzPiers
Lucy was born about 1208 in Brecknock, Wales.  She died after 1266.

 Lucy de Ros
Lucy de was born about 1225 in Helmsley Castle, North Ride Yorkshire, England.  She died after 1279 in Grey Friars, York, Yorkshire, England.

 Robert IV "1st Baron" de Ros , of Belvoir, MP
Robert IV "1st Baron" de was born in 1233 in Helmsley Castle, North Ride Yorkshire, England.  He died at the age of 52 on May 17th, 1285 in Belvoir Castle, Leicestershire, England.

 William II de Ros , of Ingmanthorpe, Sir
William II de was born about 1240 in Ingmanthorpe, Kirk Deighton, Yorkshire, England.  He died before May 28th, 1310 in Grey Friars, York, Yorkshire, England.