Planets in houses · Kendra
Mangal in the 1st house
Mars · Tanu Bhava
Mangal is the karaka (significator) of energy, courage, siblings and property. The 1st house, called Tanu Bhava, shows self, body and personality. When Mangal sits here, these matters take on its colour.
A malefic in the Lagna gives strength of will and drive, but can make one impatient or harsh and needs care for health.
The 1st house is a kendra (angular house), a pillar of the chart, so a graha here shows its results openly and strongly.
Mangal gives its best results here when it is exalted in Makara, in its own sign (Mesha and Vrishchika) or in a friendly sign, and when it is not combust.
Results are weaker if Mangal is debilitated in Karka, combust, or afflicted by malefics.
In transit (gochar)
When Mangal transits the 1st house counted from your Moon sign, the period traditionally needs more care.
A single placement is never read alone: sign, aspects, conjunctions, dasha and the whole chart change the outcome.