I Am Maximus began his career being trained by
Nicky Henderson, He made his debut ridden by
Nico de Boinville in a bumper at
Cheltenham on 24 October, 2020, winning from a field of 14 over 2 miles. He won over hurdles for the first time on December 15, 2021 at
Newbury, from a field of 13. In November 2022, I Am Maximus was moved to
Willie Mullins’ stables based at Closutton,
Bagenalstown,
County Carlow, in the
Ireland. I am Maximus was entered for the 2023
Brown Advisory Novices' Chase at
Cheltenham finishing 4th. I Am Maximus entered the
2024 Grand National and was assigned a weight of 11st 6lb, Starting as the 7/1 joint favourite he went on to win the race by 7 and a half lengths. For the
2025 Grand National I Am Maximus was assigned the heaviest weight of 11st 12lb, and finished in second place. I Am Maximus won the
2026 Grand National and carrying the top weight of 11st 12lb. After his second Grand National win on 11 April 2026, his record was 7 wins, 5 seconds, 2 thirds, from 22 races. ==Grand National record==