To win a Grand National takes a supreme effort between trainer, jockey and horse, and of course a huge slice of luck. Most racing enthusiasts would add to that equation the owner and stable lad who are each a vital link in the chain. But it is perhaps the trainer who plays the most important role of all.

There have been many trainers through the Grand National's long history who have truly stamped their name on jump racing's greatest prize. Among them are legends who, in their time, have become household names such as Fred Rimell, Neville Crump, and Jenny Pitman. In fact, their efforts are even more remarkable if you consider the fact that today's leading trainer, Paul Nicholls, hasn't a single Grand National to his name.

But perhaps the greatest achievement of them all belongs to the truly legendary diminutive Irishman Vincent O'Brien. O'Brien won three successive Grand Nationals with different horses during the 1950s – a so far completely unique feat that it is hard to imagine ever being repeated. O'Brien trained Early Mist to victory in 1953, which was followed by Royal Tan in 1954 and Quare Times the following year.

Jenny Pitman was the first ever woman to train a Grand National winner with Corbiere in 1983 – a feat she managed to repeat in 1995 with Royal Athlete, whilst Garrison Savannah was a close second when ridden by her son Mark in 1991 and her horse Superior Finish finished third in 1996. Her last National runner Nahthen Lad finished 11th in 1999.

Lady trainer Venetia Williams repeated the feat in 2009, winning the National with 100-1 chance Mon Mome. However, those looking at the Grand National 2011 betting will be sad to see Mon Mome is injured and won't run this year.

But the late, great Fred Rimell remains the most successful Grand National trainer in history having saddled four different winners with E.S.B. in 1956, Nicolaus Silver in 1961, Gay Trip in 1970 and Rag Trade in 1976.

Red Rum's trainer, Ginger McCain, also has an amazing four Grand National wins to his credit, though with just two horses, Red Rum winner in 1973, 1974 and 1977, and Amberleigh House in 2004.