Denis Cullen took over the training at Beechcourt Stables in 2009 from his father-in-law, Michael O'Brien. Before Denis embarked upon his training career he rode very successfully as an amateur rider, riding 55 winners between the flags and 55 winners on the track.

His biggest achievemement as a rider came at the Cheltenham Festival in 2003 when he partnered Sudden Shock to victory in the 4 mile National Hunt Chase for the legendary Jonjo O'Neill although this is disputed by his wife Ann-Marie who would consider the Grade 1 Ascon / Rohcon novice chase at Leopardstown as his biggest achievement, when Denis partnered Forget The Past for her father, Michael O'Brien.

Denis and his wife Ann-Marie have two wonderful children, Annalise and Christopher who are both actively involved within the yard. Michael is succeeded by his wife Ann who also is also very much involved in the day to day running of Beechcourt Stables.