When Napoleon's armies invaded Hanover, some of the German soldiers left their homeland and came to Britain, as the king - George III - was also the Elector of Hanover. The Hanovarians were stationed in Bexhill: in 1805, there were 3,570 of them in the barracks on the site of what is now Barrack Road. This large barracks ran west from St Peter's Church and this massive influx of soldiers turned what had been a village, into a substantial town. The Hanovarians were stationed here to defend Sussex and help build the necklace of Martello Towers that ringed the coast, to guard against potential landfall by Napoleon's troops. 
The Hanovarians were popular by all accounts. Caring for the troops and their horses brought considerable trade and wealth to the town and they married many of the local girls, as the marriage register in St Peters can testify. Not everyone was glad to see them though: the previous trade in the town had largely been smuggling - and the troops' duties also involved foiling their cunning plans. The sources I've read so far make no mention of troops being involved in the Battle of Sidley Green - but the smugglers must have pelted past the barracks on their way to Sidley, with the men of the Coastal Blockade hot on their heels.
There's a thriving Hanovarian Society in the town, who organised the plaque in this garden that tells you something of the troops who were buried in this corner of Holliers Hill - 150 in total. This was a town graveyard, and many years ago most of the gravestones were cleared away - and with them, all evidence of the Hanovarian soldiers. The few headstones that remain are to local people - and the only soldier I can find (Sydney Ratcliffe) died in Mesopotamia in 1917, aged 24. His name also appears on one of the town's war memorials.
Curiously enough, there's a headstone to: 'Percy Byshe Shelley Leigh Hunt' who died in 1899 aged 82. A bit of determined googling might explain that one for you!
ACCESS CASH & DASH: park in Barrack Road. SERIES WALK: From BS3: Sea Road. You CANNOT walk down the High Street as the road narrows so significantly that pedestrians are not allowed. You MUST walk down Church Street, pass the Bell Inn and St Peters Church and turn left just past the houses that skirt the church hall. Follow the lane down and turn right. Pass beneath the road bridge and Barrack Road is first left. WHEELCHAIR: Sorry - there are 4 steps down into the park from the pavement.