not now suffer the cavalry to come upon the causeway, as we had
found by experience that they were of very little service, and besides
that their horses were exposed to much danger. Finding that he could not
sufficiently annoy the enemy in his present post at Iztapalapa, where the
Mexicans had possession of the houses which were built in the water,
Sandoval advanced by a causeway to a more commanding situation[5]. When
this was noticed from Mexico, a large detachment of warriors came over in
canoes, with orders to cut the causeway in the rear of our troops. Cortes
observed this, and immediately made sail with his vessels to the relief of
Sandoval, giving orders at the same time to De Oli to march a body of
troops by the causeway for the same purpose. Having relieved Sandoval by
these means, Cortes ordered him to remove with his division from
Iztapalapa to Tepeaquilla or Tepejacac, where the church of our Lady of
Guadalupe now stands, in which many wonderful miracles have been performed.

As it was impossible for our troops to advance on the causeways, unless
their flanks were secured from attacks by water, the flotilla was
appointed to this service in three divisions, one of which was attached to
each of the three detachments of our land force: Four brigantines being
allotted to Alvarado, six to De Oli, and two to Sandoval[6]; twelve in all,
the thirteenth having been found too small for service, and was therefore
laid up, and her crew distributed to the rest, as twenty men had been
already severely wounded in the several vessels. Alvarado now led our
division to attack the causeway of Tacuba, placing two brigantines on each
flank for our protection. We drove the enemy before us from several of
their bridges and barricades; but after fighting the whole day, we were
obliged to retreat to our quarters at night, almost all of us wounded by
the incessant showers of stones and arrows of the enemy. We were
continually assailed on the causeway, by fresh troops of warriors,
carrying different banners or devices; and our brigantines were
excessively annoyed from the terraces of the houses which stood in the
water; and as we could not leave a party to keep possession of what we had
acquired during the day, the enemy repossessed themselves of the bridges
at night, and repaired and strengthened their parapets and other defences.
In some places they deepened the water, digging pits in the shallow places,
and placing the canoes in amb