The work of extending the first parallel diagonally toward the Pardaleras was still going on, when, on February 5th, the whole situation before Badajoz was changed by the appearance in the neighbourhood of a Spanish army of succour. Even before Soult had started from Seville at the New Year, Wellington had been aware of the imminence of the invasion of Estremadura, and had been consulting with his colleague La Romana as to the measures that it would be necessary to take[55]. As early as the 2nd of January La Romana had sent orders to Mendizabal, to tell him that if the French should cross the Sierra Morena in force, he was to evacuate Southern Estremadura, break the bridges of Medellin and Merida, and endeavour to defend the line of the Guadiana[56]. By later instructions (January 8) Mendizabal was directed to retire into the Sierra de San Mamed if the enemy crossed the river above Badajoz, but to throw himself upon their rear, and to hang on to them, if they crossed below, and seemed to be making for Elvas and Portugal. On the 12th, Wellington, hearing that Soult seemed to be heading towards Olivenza rather than Merida, conceived doubts as to whether he might not be intending to abandon his communications with Seville, to leave the fortresses behind him, and to march to the Tagus to co-operate with Masséna upon the Alemtejo bank of that river. On the 14th arrived the more comfortable news that the French had sat down to beleaguer Olivenza, a sure sign that they did not propose to cut themselves loose from their base and to join Masséna as a flying column. As a matter of fact, as we have seen, Soult, having been deprived of Gazan’s assistance, was too weak at this moment to dream of an incursion into Portugal, and had attacked Olivenza because he could find nothing else to do for the present. [55] Wellington, _Dispatches_, vii. p. 98, dated January 1st, to Charles Stuart reports that from Cadiz advices of December 23 he is aware that a concentration is taking place at Seville, though Mendizabal knows nothing of it. [56] Wellington’s covering letter to La Romana’s dispatch is in _Wellington Dispatches_, vii. p. 99.