Jackets with triangular overlapping front panels is often shown in Viking and Saxon art is what I refer to as a warrior coat.  There are fragments from the digs at Hedeby that show the triangular front panels.    In Saxon finds are finds of tablet weaving running down the front of the body, obviously edge decoration as shown on the helmet plaques.

See the Warrior Jacket I was wearing at Toys-for-Tots

In Viking art you can see these on the helmet plates from the Vendel (pre-Viking Sweden culture) mound burials.

You can also see the Warrior Jacket in dies found in Birka

In the Anglo-Saxon burial at Sutton Hoo, you have helm plates also showing the same warrior coats

The plates often show a belt closure on the coat.  Brooches were also used as closures for the coats.  At Birka are found Penannular brooches or ringed pins found as closures at hip level.

You can also see a very similar warriors coat used throughout northern regions from England to China!