The emergence of magnetic flux through the solar photosphere in the vicinity of a filament can trigger a coronal mass ejection (CMEs), or alternatively it could stabilise the filamentary structure. Both modelling and observational studies have shown that whether a filament is activated depends on the position, orientation and strength of the emerging flux. The emergence of a small bipole underneath a quiescent circular filament on 18-July-2014 causes the filament to split, to erupt and in the process to form a new filament arcade, which also undergoes an eruption. We propose a mechanism to explain this activity, based on SDO/AIA and HMI observations, and we are currently working on simulations to reproduce this.