In Europe after the introduction of gunpowder artillery, fortifications actually got lower; in India this strategic advantage was developed through the use of the fausse-braye
, which was a lower outer fortification.
In terms of discrepancies unlikely to reflect successive architectural changes to the Castelo, the sources mostly diverge with respect to details of the landward fausse-braye (barreira) and the dry ditch.
0406:07:009:001 departs from most other draughts in four interesting respects--a) an inward-bent north curtain wall (replicated in NMM F1959 P/43(7) but in no other English draught); b) a somewhat narrower dry ditch; c) an oversized polygonal bridgehead bastion (full barbican); and d) a fausse-braye (barreira) hugging the base of the Castelo wall from the root of the great south-east couraca past the middle cubelo (whose base it covered) to the north-east cubelo.
Early twentieth-century photographs still show remnants of a similar low fausse-braye along the base of the restored wall above the Degraos da ribeira, between the twin towers and the Hotel Continental (Plate 6).
0406:07:009:001 and to the BNF-type plans, a stubby tower or redoubt (traves) (either round or more probably square--on the strength of the Krigsarkivet draught) dominated the middle of the curtain wall above the degraos, with a corresponding low traves in the middle of the fausse-braye (barreira).
The latter is to some extent an "inside-out" homologue of Tangier's former Porta do campo--the main gateway of Bab Agdal extends back from the town wall, instead of projecting into the bailey between the curtain and fausse-braye as at Tangier.
The Portuguese chronicles confirm that in the 1430s-60s, before the digging of the land-front's large dry ditch so dramatically featured in Hollar's "View from Peterburgh Tower", a fausse-braye (barreira) stretched in front of the medieval main curtain wall (just as it did along the south wall).
Danzilho's work is attested above all in Miranda do Douro (pentagonal bastion attached to a new section of the fausse-braye), 23 in Almeida (Almeida's moat and a fausse-braye with two tiers of gunports and circular comer bastions), in Castelo Rodrigo (torre de menagem [castle keep] and barbican bastion), in Castelo Bom (comer gun-tower and other elements), and elsewhere in the Ribacoa region.
Given the layout of Alcacer's fortifications and the construction stages discussed below, construction seems to have been expedited by partly lining the ditch with smaller stones taken in situ from an old fausse-braye on the east and south side of the town.
There is perhaps no better succinct explanation of what a fausse-braye was, how it functioned, and what its merits and drawbacks were thought to be at a time when in its original form it had already become obsolete, than the relevant passage in Antoine de Ville's Fortifications, published in Lyon in 1639.
Rising about 8 to 10 French pieds above the bottom of a dry ditch, or 3 to 4 pieds above the water level of a wet one, with a parapet at the level of the surrounding open terrain, a fausse-braye shielded the lower part of the main fortress wall, and arguably constituted a superior firing position against attackers seeking lodgment on the ditch counterscarp or down in a dry ditch.
It is safe to say that no other part of Alcacer's ground plan has been more misunderstood and misinterpreted, and the same is true of various references to the town's fausse-braye in the Portuguese documents and chronicles.