 Although the siege tied up a large number of Spanish , British and Portuguese troops , Wellington accepted this as part of his strategy since a similar number of French troops were also engaged . However , in January 1811 , Victor 's position began to deteriorate . Soult ordered Victor to send almost a third of his troops to support Soult 's assault on Badajoz , reducing the besieging French army to around 15 @,@ 000 men . Victor had little chance of making progress against the fortress city with a force of this strength , nor could he withdraw — the garrison of Cádiz , if let loose , was large enough to overrun the whole of Andalusia . 
