On April 22, 1979, from 0840 to 1050 UT, conditions varied from quiet to disturbed both on the ground and in the geomagnetotail corresponding to the northward and southward interplanetary magnetic field (IMF) conditions, respectively. In this interval, ISEE 3 monitored the solar wind, 206 RE upstream and 82 RE to the dawnside of the Earth. Very near the center of the tail, ISEE 1 and ISEE 2 were 17 and 16 RE behind the Earth. IMP 8 was also located in the tail at about 35 and 6 RE above the expected position of the current sheet and 16 RE to dawnside of the Earth. The combination of the three spacecraft monitoring the tail in key locations, the strong northward IMF switching to southward, and the excellent coverage of the midnight sector by the North American magnetometer chains make this a unique and ideal case to study. A global perspective of the observations of these four spacecraft, observations of two synchronous spacecraft, GOES 2 and GOES 3, and of ground-based magnetometers is presented herein. For IMF northward, a flapping wave in the tail is seen to propagate away from the Earth at about 95 km/s, while simultaneous plasma convection in the center of the tail was usually in the reverse direction, toward the Earth. A dipolarization of the tail field was observed by the ISEE pair near the current sheet center, and it moved toward the Earth at close to the speed of the convecting plasma. The current sheet was significantly twisted at the position of IMP 8 under the influence of the IMF. By conditions, even though Bz was northward. For IMF southward, a reconnection point appeared to form inside the location of ISEE, and then it moved down the tail rapidly. The onset of this activity at the ISEE pair was simultaneous with the onset of ground activity. Plasma convection was mainly away from the Earth. The current sheet became bent at 16 RE, and the bend appeared to move down the tail some time after the plasma flow was earthward. Highly structured magnetic field were observed at the ISEE pair, the configuration of which is difficult to discern with only two spacecraft. A substorm that developed rapidly after the arrival of southward IMF, accompanied by an enhanced electrojet at L values normally well inside synchronous orbit, had little effect at synchronous orbit at 0100 LT. However, the near-tail region was immediately affected. Nevertheless, despite the strong southward fields observed in the tail and the strong flows, the energetic electron data indicate that the ISEE spacecraft remained on closed field lines for the entire period under study. The extensive documentation of the input and output of this event should make it an excellent candidate for computer simulation.¿ 1997 American Geophysical Union