Last year's winner Many Clouds is among 126 entries for the Grand National, the highest number for the famous Aintree feature since 2008.
Five of the first six horses home last year are entered again with runner-up Saint Are (trainer Tom George), fourth Alvarado (Fergal O'Brien), fifth Shutthefrontdoor (Jonjo O'Neill) and sixth Royale Knight (Newland) all engaged for the race on April 9.
The Oliver Sherwood-trained Many Clouds will be attempting to emulate the great Red Rum, the last horse to win back-to-back Nationals in 1973-74.
Dr Richard Newland's 2014 winner Pineau De Re is also on the list.
Champion Irish jumps trainer Willie Mullins has entered seven, including Cheltenham Gold Cup contender Don Poli and dual Festival winner Sir Des Champs.
Further notable contenders from Ireland could include Gilgamboa, 2014 Gold Cup hero Lord Windermere and Irish National winner Thunder And Roses.
Dual King George winner Silviniaco Conti is Paul Nicholls' standout contender, with Triolo D'Alene in for Nicky Henderson and Soll heading David Pipe's team.