  Stress accumulation-relaxation meta-models of pulsar glitches make precise,
microphysics-agnostic predictions of long-term glitch statistics, which can be
falsified by existing and future timing data. Previous meta-models assume that
glitches are triggered by an avalanche process, e.g. involving superfluid
vortices, and that the probability density function (PDF) of the avalanche
sizes is history-independent and specified exogenously. Here a recipe is
proposed to generate the avalanche sizes endogenously in a history-dependent
manner, by tracking the thresholds of occupied vortex pinning sites as a
function of time. Vortices unpin spasmodically from sites with thresholds below
a global, time-dependent stress and repin at sites with thresholds above the
global stress, imbuing the system with long-term memory. The meta-model
predicts PDFs, auto- and cross-correlations for glitch sizes and waiting times,
which are provisionally inconsistent with current observations, unlike some
previous meta-models (e.g. state dependent Poisson process), whose predictions
are consistent. The theoretical implications are intriguing, albeit uncertain,
because history-dependent avalanches embody faithfully the popular, idealized
understanding in the literature of how vortex unpinning operates as a driven,
stochastic process. The meta-model predicts aftershocks, which occur with
larger than average sizes and longer than average waiting times after the
largest, system-resetting glitches. This prediction will be tested, once more
data are generated by the next generation of pulsar timing campaigns.
