  We present results of long-term high-frequency VLBI monitoring of the
relativistic jet in 3C279, consisting of 18 epochs at 22 GHz from 1991 to 1997
and 10 epochs at 43 GHz from 1995 to 1997. Three major results of this study
are: apparent speeds measured for six superluminal components range from 4.8 to
7.5 c (H_{0}=70 km s^{-1} Mpc^{-1}, q_{0}=0.1), variations in the total radio
flux are due primarily to changes in the VLBI core flux, and the uniform-sphere
brightness temperature of the VLBI core is about 1 x 10^{13} K at 22 GHz after
1995, one of the highest direct estimates of a brightness temperature. If the
variability brightness temperature measured for 3C279 by Lahteenmaki & Valtaoja
is an actual value and not a lower limit, then the rest-frame brightness
temperature of 3C279 is quite high and limited by inverse Compton effects
rather than equipartition. The parsec-scale morphology of 3C279 consists of a
bright, compact VLBI core, a jet component (C4) that moved from about 2 mas to
about 3.5 mas from the core during the course of our monitoring, and an inner
jet that extends from the core to a stationary component, C5, at about 1 mas
from the core. Components in the inner jet are relatively short-lived, and fade
by the time they reach about 1 mas from the core. The components have different
speeds and position angles from each other, but these differences do not match
the differences predicted by the precession model of Abraham & Carrara.
Although VLBI components were born about six months prior to each of the two
observed gamma-ray high states, the sparseness of the gamma-ray data prevents a
statistical analysis of possible correlations.
