Elder Futhark, an early runic script, was definitely used in 160AD in Denmark. Based on linguistic clues, some people think that it is much older.
One of the clues cited is that it is written both left-to-right and right-to-left, like Greek or Etruscan before 200 BC. Another clue is that there are characters for sounds which linguists believe had faded from the spoken language by 160 AD.
Futhark is an unusual alphabet in that it does not use either of the alphabetization orders that come from Ugaritic, unlike almost all other alphabets. It takes its name from the first six letters: f, u, th, a, r, and k. I think its unusual ordering argues for a single person developing the script –perhaps a trader who wandered down to Greece and brought the idea of writing back — instead of it evolving gradually among a group of people. (Perhaps Bob Futhark brought the script to Scandinavia, and he thought it would be fun to spell out his name in the first few letters.) It is also possible that my imagined trader simply never learned the standard ordering, so came up with his own.
You might think that the ordering just wasn’t important to them, and the f-u-th-a-r-k is just based on perhaps one person who happened to write them down in that order. However, the ordering was perhaps more important in Futhark than most writing systems: in an alternate glyph scheme, characters were written based on their place in the ordering. Characters were grouped into three sets of eight and could be represented as two sets of horizontal lines on either side of a vertical line. The number of lines on the left represented which set of three the letter was in; the number of lines showed which number in the set of eight it was. (You could imagine this as an early octal representation.)
Futhark had a very angular look to it, which probably came from the common writing technology of that place and time: scratching or carving into hard objects like wood, bone, and stone. Straight lines are easier to make than curved when carving.