The Messerschmitt Me 262 was not exactly the first turbojet-powered fighter in the world (that honor was for the Heinkel He-280) but it was the first turbojet fighter that entered active service as the first in the world.

The first flight was made without turbojets, but with Jumo 210G piston engines, due to problems and late delivery of the new power source jet to come. All but one (Me-262 V3) of the first eight airframes were lost during test-flights

The first production model was the Me-262A-1a single seat interceptor, and was know under the name 'Schwalbe'. This first model was powered by two 900 kg. thrust Jumo 004B-1 engines.

Four 30 mm MK 108 cannons, and later added 12x 55 mm R4M rocket missals under each wing was standard armament for this type.

The first 28 production model Me-262 were delivered to the Luftwaffe  in June 1944. The first interception missions were flown by the EKdo 262 trials unit. By the end of October of that same year 315 Me-262's were accepted by the Luftwaffe, and by the end of April 1945 1065 Me-262's were in active service in at least 4 configurations. (probably many more)

The first 'arrival' of a Me-262 in air-combat with the allied forces must of been a shock to those pilots, it had almost 100 Kph more speed, something that was very important in those days. If it had arrived earlier and in greater numbers the Me-262 could of made a difference in defeating the Nazi's. It would have almost certainly delayed the allied victory for moths or even years..

Underneath you can find the characteristics of the Me-262A-1a, B-2, and C-1a