Christmas Day football, on a battlefield.

It happened just once, it wasn't orginised by either side but was something that 'just happened'. Although the football aspect was far from universal - in fact it may have only occured on one or two places - the face to face meetings are well documented. Or at least on the British/German lines. More than a few of the Germans had relatives in England, and several asked British troops if they would pass on letters to them. (I seem to recall one British officer being rather taken back when it turned out that his counterpart's aunt and uncle ran the shop at the end of the road he lived on).

In later years too much had happened for such get-togethers to happen. However the German's did often call across the trenches at Christmas to warn the British when someone at HQ had decided to shell part of the trenches. It appears that the German's never gave false information or warnings in this regards, nor tried to attack after giving such warnings.

There is at least one recorded occasion in the Imperial War Museums collection relating to interviews with soldiers after the war indicating that the German's did indeed declare unofficial truces at Christmas on otherwise quiet parts of the line. This was usually a case of some good natured sing-offs between German's and Brits (the Welsh usually won these), and warnings when someone had decided to spoil Christmas by shelling. (At least this was the case in a couple of sections where the trenches were close enough together the troops in the trenches could shout at each other).

Gifts (of the none exploding type) and letters were not shared after the first year, as no one was stupid enough to stick their heads out of the trenches.