Short answers, pulled from the story.
The year 1086 marks the first written record of the land that would become Lancashire. The Domesday Book listed much of this territory under Yorkshire and Cheshire rather than as a distinct county.
In 1182 the county was officially established with borders touching Cumberland, Westmorland, Yorkshire, and Cheshire. It split into six hundreds: Amounderness, Blackburn, Leyland, Lonsdale, Salford, and West Derby.
the 1st of April 1974 brought radical change under the Local Government Act 1972. The southeast portion became part of Greater Manchester while the southwest joined Merseyside and Widnes and Warrington transferred to Cheshire.
Lancaster achieved city status in 1937 after centuries as a historic county town. Multiple boundary extensions occurred throughout the 20th century as urban areas expanded outward.
Gragareth near Whernside reaches 627 meters as the highest point in the ceremonial county though Green Hill sometimes claims this title. Coniston Old Man at 803 meters holds the record for the historic county.