Who is known as The Invincibles in English football?

Context: In football, "The Invincibles" is a nickname used to refer to the Preston North End team of the 1888–89 season, managed by William Sudell, and the Arsenal team of the 2003–04 season managed by Arsène Wenger. Preston North End earned the nickname after completing an entire season undefeated in league and cup competition, while Arsenal were undefeated in the league in a run that stretched to a record 49 games. The actual nickname of the Preston team was the "Old Invincibles" but both versions have been in use.

Answer: Preston North End & Arsenal Football Club