Yep, Landrover rebranded it numerous times, latest is defender, as you say they called it defender only to separate from disco.
We may or may not like certain years of the rebrand, however its been the same model under the make all along.
The proof is in the body shape, and the people that actually made it saying so.
Good article on it here
Land Rover - History, Trivia & Fast Facts
"AND ROVER BECOMES ITS OWN BRAND
The success of the Series Land Rover and “Rangie” prompted the transition of Land Rover from a product line to full brand in 1978 – under the stewardship of British Leyland before it was subsequently renamed the Rover Group in 1988 during a messy period in the British car industry. In 1994, an ambitious BMW purchased the Rover Group from British Aerospace – but a combination of German mismanagement and the British manufacturer’s deep-rooted issues resulted in Land Rover being sold to Ford six years later (for a then US$2.8billion) while Rover went to a consortium (for a nominal £10)."
"SOLID DEFENCE
The Series Land Rover had eventually become the Ninety and One Ten – two versions named after their wheelbases in inches (approximately) – before being badged Defender 90 and Defender 110 from 1991. Production finally ended in January 2016, 68 years after the original rolled off the same Solihull, UK, assembly line. About two million had been built, and between 65 and 70 per cent of these are estimated to still be running today."

