An inkjet printing apparatus comprises at least one printhead which comprises at least one ink chamber and a plurality of nozzles, at least one ink container remote from the printhead, an ink delivery system comprising a source of gas under pressure operable to supply ink from said remote ink container to said ink chamber on the printhead, a priming device arranged to prime at least one printhead and comprising a connecting assembly to connect the source of gas under pressure to the printhead to be primed, and a controller to control the flow of gas through said connecting assembly to provide upon demand gas under pressure to the printhead in order to cause a flow of ink from the ink chamber through the nozzles to prime the printhead.