  Fossil groups are galaxy structures that probably underwent a nearly complete
fusion of all intermediate magnitude galaxies into a single large central
dominant galaxy. However, the formation and evolution processes of these
structures are still not well understood. In order to test this scenario and
its implications we studied the fossil group RXJ1119.7+2126, based on available
spectroscopy of the galaxies in the low density large scale region around the
fossil group and deep B and R band imaging of its close vicinity and three
comparison fields. We used spectroscopic data to investigate the degree of
isolation of RXJ1119.7+2126 in terms of bright neighbour galaxies. The imaging
data were used to derive the color magnitude relation and select faint galaxies
statistically belonging to this structure. The structure appears as a very
isolated group exhibiting a red sequence in the color magnitude relation with
characteristics close to the red sequences already observed for other fossil
groups. All these results can be interpreted consistently in the framework of
the building up process generally proposed for fossil groups.
