Lithuania: silver half-grosz of Sigismund the Old of Poland, 1512 Obverse: Vytis (charging knight; symbol of Lithuania). Reverse: crowned eagle. Hammered silver, 19.7 mm, 1.21 g. A very early dated coin struck in the reign of Sigismund I ("The Old"), king of Poland, at a time when Lithuania was under Polish rule. The date is expressed as "IZ" (12) at the end of the obverse legend, so (15)12. I bought this attributed as "1 grosz", but I rather suspect it is a half-grosz.
I love old coins with my ancestors on them, even though they never get a mention in the description. Seriously, how do they fix the date on one like that, is it by the period of reign, an estimate, in other words? Unless there's one on there, I'm just not making it out.
If you think the late-medieval 2's are weird, you should see the 4's and 7's. @tibor can show us some examples of that. Quite a few places began dating coins in the 1400s and 1500s, but at first, many of them only put the last two digits of the date on there, as in this case.
I don't know why, but a lot of Polish-Lithuanian coins use that Z for 2 numeral. For example, this 1614 3 polker is 1/24 of something (I forget what). Or this 1521 City of Schweidnitz 1/2 groschen Louis II looks like 15:Z1 for the date
On the left image the date is between 10:00 and 12:00. The "4" looks like a squared of ribbon. The "7" looks like an upside down "V".
On this piece the last two digits of the date (14)95 show at 11:00. The "5" looks like a "7" with a wavy top.
These are really interesting. The influence of Arabic shows through more clearly on some of the older numeral forms. (Image swiped from Wikipedia: Arabic numerals)