Henri Lansbury was with Norwich until the age of 9 when he followed Roy Massey to Arsenal. By the tme he was 14, he was training with Arsenal's Under-18s and is seen as one of their brightest prospects. A central midfielder, Henri played for England in the UEFA Under-17 competition held in May but was injured in the semi-final win over France and so missed the final which England won

Lansbury made his first team debut for Arsenal in the autumn of 2008 in the 3-0 Carling Cup victory over Sheffield United.

On Transfer Deadline Day (2nd February 2009), Henri was loaned out to Scunthorpe. He helped them to win promotion to the Championshp and reach the final of the Johnstone Paint Trophy

Lansbury then competed for England in the European Under-19 championship; and reached the final before losing 2-0 to hosts Ukraine. Scunthorpe manager Nigel Adkins then expressed his interest in having Lansbury return to Scunthorpe.

On 1st September 2009, Henri was loaned to Malky Mackay's Watford until 31st Decembr 2009