Original: In 1972 an extension of the M1 was opened into central Leeds as the Leeds South Eastern Motorway where it met the Leeds South Western Motorway (M621) coming north-east from the M62 at junction 3.
Simplified: In 1972 an extension of the M1 was opened into central Leeds. It was called the Leeds South Eastern Motorway. It meets the Leeds South Western Motorway (M621) at Junction 43.