First in France. A stable observation and reconnaissance aircraft that served with the Royal Flying Corps and later, Royal Air Force during the Great War.
It proved to be highly stable, making it great for spotting artillery, relsying enemy movements and taking photos for reconnaissance missions. Stability was key for reconnaissance aircraft of the day, and it served its job well.
However, such stability came at a cost. The plane had poor maneuverablility, with early versions having wing warping (only the B.e.2c variant onwards had ailerons). To make things worse, it had almost no way of defending itself. The observer was placed in front of the aircraft, and often didn't have a gun, and when guns were placed, often were in an awkward position that didn't give much firing range.
Nonetheless, a fighter is not what is was built for, and reportedly did score a few kills on unlucky German pilots. It had one job, reconnaissance, and it excelled in it.