  After three years of no unusual activity, Anomalous X-ray Pulsar 1E
1048.1-5937 reactivated in 2007 March. We report on the detection of a large
glitch (Delta(nu)/nu =1.63(2)X~10^{-5}) on 2007 March 26 (MJD 54185.9),
contemporaneous with the onset of a pulsed-flux flare, the third flare observed
from this source in 10 years of monitoring with the Rossi X-ray Timing
Explorer. Additionally, we report on a detailed study of the evolution of the
timing properties, the pulsed flux, and the pulse profile of this source as
measured by RXTE from 1996 July to 2008 January. In our timing study, we
attempted phase coherent timing of all available observations. We show that in
2001, a timing anomaly of uncertain nature occurred near the rise of the first
pulsed flux flare; we show that a likely glitch (Delta(nu)/nu =2.91(9)X10^{-6})
occurred in 2002, near the rise of the second flare, and we present a detailed
description of the variations in the spin-down. In our pulsed flux study, we
compare the decays of the three flares and discuss changes in the hardness
ratio. In our pulse profile study, we show that the profile exhibited large
variations near the peak of the first two flares, and several small short-term
profile variations during the most recent flare. Finally, we report on the
discovery of a small burst 27 days after the peak of the last flare, the fourth
burst discovered from this source. We discuss the relationships between the
observed properties in the framework of the magnetar model.

Astrophysics