Sentence:  By the 1850s, there was a thriving trade in selling the horses to the Indian Army as 'remounts'. Between 1834 and 1937, more than 300,000 <WSD>Walers</WSD> were sent to India. 
Meaning of the word marked with <WSD> tags:  A breed of light saddle horse from Australia, once favoured as a warhorse.